EP3826863B1 - Bi-modulus metal cords - Google Patents

Description

The present invention relates to metal cords which can be used for reinforcing tires for vehicles. By tire is meant a tire intended to form a cavity by cooperating with a support element, for example a rim, this cavity being capable of being pressurized to a pressure greater than atmospheric pressure. A tire according to the invention has a structure of substantially toroidal shape.

The state of the art is known for tires for passenger vehicles comprising a crown and two sidewalls. These tires conventionally comprise a carcass reinforcement anchored in two beads and surmounted radially by a crown reinforcement itself radially surmounted by a tread, the crown reinforcement being joined to said beads by the two sidewalls. The carcass reinforcement comprises a single carcass ply comprising corded carcass reinforcement elements. The crown reinforcement comprises a working reinforcement comprising two working plies comprising working reinforcing cord elements, the working reinforcing cord elements of the two plies making angles with the circumferential direction of the tire in opposite orientations by work slick to side. The crown reinforcement also comprises a hooping reinforcement comprising a single hooping ply comprising textile cord elements for hooping reinforcement. The carcass and work reinforcement wire elements are arranged so as to define, in the crown, a triangular mesh. Such a tire is described in particular in US2007006957 . Due to the presence of two working plies, the textile wire elements for reinforcing the hooping of US2007006957 have relatively weak mechanical properties.

We know of WO2016/166056 a tire in which the working reinforcement comprises a single working ply. Thus, the crown reinforcement of the tire is lightened. In this tyre, the triangular mesh is ensured by the particular arrangement, in the crown, of the carcass reinforcing, working and hooping wire elements. WO2016/166056 describes wire elements for textile and metal hooping reinforcement. Specifically, WO2016/166056 describes a cable 3.26 forming a hooping reinforcing wire element comprising a single layer of N=3 metal wire elements wound in a helix, each metal wire element consisting of a steel monofilament and has a diameter equal to 0.26 mm. Due to the presence of a single working ply, the hooping reinforcement wire elements of WO2016/166056 have relatively high mechanical properties.

In US2007006957 and WO2016/166056 , the wire-based hooping reinforcement elements must ensure a hooping function of the tire, that is to say to counterbalance the effects of centrifugal force linked to the speed of rotation of the tire, such as for example a deformation of the profile of the tire or a modification of the contact area when high stresses are exerted on the tire. In this respect, the tire of US2007006957 has wire elements for hooping reinforcement whose hooping capacity can be improved.

Furthermore, it is desirable to have tires emitting the least possible noise, in particular the so-called “coast-by” noise which is for example evaluated by a measurement method in accordance with the ISO13325:2003 standard. In this respect, the tire of WO2016/166056 emits a relatively high noise.

Furthermore, whether in the case of the tire of US2007006957 or tire WO2016/166056 , due to a relatively high cost of textile materials, in particular aramid, the textile wire elements for hooping reinforcement are relatively expensive. On the other hand, at high temperatures, for example at high speed, the mechanical properties of these textile materials deteriorate significantly due to their low thermal stability. Finally, the textile cord elements have little or no protective role vis-à-vis mechanical attack, for example perforations, to which the tire is subjected.

Cables comprising metallic wire elements are disclosed in WO 2016/083265 and WO 2016/189073 .

The object of the invention is to provide a wire-based metal hooping reinforcing element making it possible both to perform the hooping function of a tire and at the same time to reduce the noise emitted by the tire.

CABLE ACCORDING TO THE INVENTION

• 5 GPa ≤ M₁ ≤ 16 GPa, et
• 40 GPa ≤ M₂ ≤ 160 GPa, et
• 3 ≤ M₂/M₁,

M₁ et M₂ étant exprimés en GPa avec :

• M₁=10 / A₁₀₀ avec :
  • A₁₀₀ étant l'allongement, exprimé en %, du câble sous un effort de 100 MPa, et
• M2=[(F₄₀-F₃₀) / (A₄₀-A₃₀)] / S avec :
  • S étant la section, exprimée en mm², telle que S=MI /Mv avec :
    • ▪ MI étant la masse linéique des éléments filaires métalliques, exprimée en g par m de câble,
    • ▪ Mv étant la masse volumique des éléments filaires métalliques, exprimée en g par cm³,
  • F₄₀ étant la force, exprimée en daN, égale à 40 % de la force théorique maximale F_t du câble,
  • F₃₀ étant la force, exprimée en daN, égale à 30 % de la force théorique maximale F_t du câble,
  • A₄₀ étant l'allongement du câble, exprimé en %, à 40% de la force théorique maximale F_t du câble,
  • A₃₀ étant l'allongement du câble, exprimé en %, à 30% de la force théorique maximale F_t du câble,
  avec F_t= MI x Rm /Mv, exprimée en daN, avec Rm étant la résistance mécanique à rupture moyenne, exprimée en MPa, des éléments filaires métalliques constituant la couche unique.

To this end, the subject of the invention is a cable comprising a single layer of metal wire elements wound in a helix, each metal wire element of the layer describing, when the cable extends in a substantially rectilinear direction, a trajectory in the form of helix around a main axis substantially parallel to the substantially rectilinear direction, so that, in a section plane substantially perpendicular to the main axis, the distance between the center of each metal wire element of the layer and the main axis is substantially constant and equal for all metallic wire elements of the layer, cable in which:

• 5 GPa ≤ M ₁ ≤ 16 GPa, and
• 40 GPa ≤ M ₂ ≤ 160 GPa, and
• 3 ≤ M ₂ /M ₁ ,

M ₁ and M ₂ being expressed in GPa with:

• M ₁ =10 / A ₁₀₀ with:
  • A ₁₀₀ being the elongation, expressed in %, of the cable under a force of 100 MPa, and
• M2=[(F ₄₀ -F ₃₀ ) / (A ₄₀ -A ₃₀ )] / S with:
  • S being the section, expressed in mm ² , such that S=MI /Mv with:
    • ▪ MI being the linear mass of the metallic wire elements, expressed in g per m of cable,
    • ▪ Mv being the density of the metallic wire elements, expressed in g per cm ³ ,
  • F ₄₀ being the force, expressed in daN, equal to 40% of the maximum theoretical force F _t of the cable,
  • F ₃₀ being the force, expressed in daN, equal to 30% of the maximum theoretical force F _t of the cable,
  • A ₄₀ being the elongation of the cable, expressed in %, at 40% of the maximum theoretical force F _t of the cable,
  • A ₃₀ being the elongation of the cable, expressed in %, at 30% of the maximum theoretical force F _t of the cable,
  with F _t =MI x Rm /Mv, expressed in daN, with Rm being the mechanical strength at average rupture, expressed in MPa, of the metallic wire elements constituting the single layer.

On the one hand, the cable according to the invention, as demonstrated by the comparative tests described below, makes it possible to reduce the noise emitted by the tire due to a value of M ₁ ranging from 5 GPa to 16 GPa. M ₁ is representative of the modulus of the cable for the forces undergone by the cable during rolling under normal conditions and therefore representative of the conditions under which the so-called “coast-by” noise is emitted. Below 5 GPa, in the case of a relatively low force undergone, the cable would deform too much and would then reach the range of elongations corresponding to the much higher modulus M ₂ , a modulus which would then be harmful in particular to noise. emitted by the tire but also to its comfort. Above 16 GPa, the cable would have too high a modulus and would therefore be relatively rigid, thus increasing the noise generated by the rolling of the tire.

On the other hand, the cable according to the invention, as demonstrated by the comparative tests described below, also has excellent shrinking capacity due to a value of M ₂ ranging from 40 GPa to 160 GPa. M ₂ is representative of the modulus of the cable for the forces undergone by the cable when strong stresses are exerted on the tire. Below 40 GPa, the cable will not be able to ensure sufficient shrinking capacity to counterbalance the effects of centrifugal force linked to the speed of rotation of the tire. Above 160 GPa, there is a risk of damaging the cable in the event of significant imposed deformation, for example when crossing an obstacle such as a curb, a bump or a pothole.

Finally, the M ₂ /M ₁ ratio ensures that both the lowest possible noise emitted and excellent binding capacity of the cable according to the invention are obtained and that performance is not sacrificed by relative to another.

The values of A ₃₀ and A ₄₀ are obtained by determining, on a force-elongation curve obtained by pulling a cable under the conditions of standard ASTM D2969-04 of 2014, respectively the values at 30% and 40% of the theoretical force maximum F _t of the cable. Similarly, the value of A ₁₀₀ is obtained by determining, on a force-elongation curve obtained by pulling a cable under the conditions of standard ASTM D2969-04 of 2014, the elongation of the cable under a force of 100 MPa.

Mean mechanical resistance Rm means the average of the mechanical resistance of the metal wire elements constituting the single layer weighted by the number of these metal wire elements. Thus, for example, if all the metal wire elements have the same mechanical resistance, the average mechanical resistance Rm is equal to the mechanical resistance of each metal wire element. The mechanical strength or mechanical breaking strength of each metal wire element is its maximum tensile breaking stress and is determined by applying the ASTM D2969-04 of 2014 standard to each metal wire element.

The linear mass MI of the metal wireframe elements is determined, for example, by applying the ASTM D2969-04 standard of 2014 to each metal wireframe element, then by summing the values of the linear masses of each metal wireframe element.

The density Mv of the metal wire elements is the density of the metal constituting each of the metal wire elements. For example, for a carbon steel used in the field of tires, the density Mv is equal to 7.8 g.CM ⁻³ .

In addition to the advantages described above, the cable according to the invention allows the manufacture of a hooping reinforcement, due to the use of metallic wire elements, which are less expensive, more thermally stable and confer mechanical protection on the tire. compared to the textile wire elements for hooping reinforcement of the state of the art described in US2007006957 and WO2016/166056 . In addition, the use of metallic wire elements makes it easier to check the hooping reinforcement by radiography after its manufacture.

The values of characteristics M1, M2, M2/M1, M1', M1", Ft, MI, Mv, Rm as well as that the other characteristics described below are measured on or determined from the cables either directly after manufacture, that is to say before any step of embedding in an elastomeric matrix, or extracted from an elastomeric matrix, for example d a tire, and having then undergone a cleaning step during which any elastomeric matrix, in particular any material present inside the cable, is removed from the cable. To guarantee an original state, the adhesive interface between each metal wire element and the elastomeric matrix must be removed, for example by electrochemical process in a bath of sodium carbonate. The effects associated with the shaping step described below, in particular the elongation of the cables, are canceled by the extraction of the sheet and of the cable which resume, during the extraction, substantially their characteristics before the shaping step.

A person skilled in the art will be able to vary the geometric characteristics of the cable in order to vary the values of M ₁ and M ₂ within the limits of the intervals of the invention. Thus, in order to increase the modulus M ₁ , the radius of curvature of the metal wire elements can be reduced, which amounts to increasing the diameter of the internal arch defined by the metal wire elements. Conversely, in order to lower the module M ₁ , the radius of curvature of the metallic wire elements can be increased, which amounts to reducing the diameter of the internal vault. It is possible, in order to increase the modulus M ₂ , to lower the helix angle of each metallic wire element, which amounts to reducing the diameter of the internal arch. Conversely, it is possible, in order to lower the module M ₂ , to increase the helix angle of each metallic wire element, which amounts to increasing the diameter of the internal vault.

It is recalled for this purpose that the helix angle α is a quantity well known to those skilled in the art and can be determined by the following iterative calculation comprising 3 iterations and in which the index i indicates the number of the iteration 1, 2 or 3. Knowing the structural elongation As expressed in %, the helix angle α(i) is such that α(i)=Arcos [ (100/(100+As) × Cos [ Arctan (( π × Df) / (P × Cos(α(i-1)) × Sin(π/N)) ] ], where P is the pitch expressed in millimeters at which each metal wire element is wound, N is the number metallic wireframe elements of the layer, Df is the diameter of each metallic wireframe element expressed in millimeters, Arcos, Cos and Arctan and Sin denoting respectively the arcosine, cosine, arctangent and sine functions. that is, for the calculation of α(1), we take α(0)=0. At the third iteration, we obtain α(3)=α with at least one significant digit after the decimal point when α is expressed in degrees.

The structural elongation As, a quantity well known to those skilled in the art, is determined for example by applying the ASTM D2969-04 standard of 2014 to a cable tested so as to obtain a force-elongation curve. The As is deduced from the curve obtained as the elongation, in %, corresponding to the maximum slope of the force-elongation curve. As a reminder, an elongation force curve includes, moving towards increasing elongations, a structural part, an elastic part and a plastic part. The structural part corresponds to the structural elongation As resulting from the ventilation of the cable, that is to say the vacant space between the various metallic wire elements constituting the cable. The elastic part corresponds to an elastic elongation resulting from the construction of the cable, in particular the angles of the various layers and the diameters of the wires. The plastic part corresponds to the plastic elongation resulting from the plasticity (irreversible deformation beyond the elastic limit) of one or more metallic wire elements.

It is recalled that the pitch P at which each metallic wire element is wound is the length traveled by this wire element, measured parallel to the axis of the cable in which it is located, at the end of which the wire element having this pitch performs a turn complete around said axis of the cable.

The helix diameter Dh, expressed in millimeters, is calculated according to the relation Dh=P × Tan(α) / π in which P is the pitch expressed in millimeters at which each metal wire element is wound, α is the angle of helix of each metallic wire element determined above and Tan the tangent function. The helix diameter Dh corresponds to the diameter of the theoretical circle passing through the centers of the metallic wire elements of the layer in a plane perpendicular to the main axis of the cable.

The metallic wire elements of the cable according to the invention define an internal vault of the cable of diameter Dv. The arch diameter Dv, expressed in millimeters, is calculated according to the relationship Dv=Dh-Df in which Df is the diameter of each metallic wire element and Dh the helix diameter, both expressed in millimeters.

The radius of curvature Rf of each metal wire element, expressed in millimeters, is calculated according to the relationship Rf=P/(π × Sin(2α)) in which P is the pitch expressed in millimeters of each metal wire element, α is l helix angle of each metallic wire element and Sin the sine function.

The cable according to the invention comprises a single layer of metal wire elements wound in a helix. In other words, the cable according to the invention comprises only one, not two, nor more than two layers of metal wire elements wound in a helix. The layer is made up of metal wireframes, i.e. several metal wireframes, not a single metal wireframe. In one embodiment of the cable, for example when the cable comes from its manufacturing process, the cable as defined above consists of the layer of metallic wire elements wound, in other words the cable does not include any metallic wire element other than those of the layer.

The cable according to the invention has a single helix. By definition, a single helix cable is a cable in which the axis of each metal wire element of the layer describes a single helix, unlike a double helix cable in which the axis of each metal wire element describes a first helix. around the axis of the cable and a second helix around a helix described by the axis of the cable. In other words, when the cable extends in a substantially straight direction, the cable comprises a single layer of metal wire elements wound together in a helix, each metal wire element of the layer describing a path in the form of a helix around of a main axis substantially parallel to the substantially rectilinear direction so that, in a section plane substantially perpendicular to the main axis, the distance between the center of each metal wire element of the layer and the main axis is substantially constant and equal for all metallic wireframe elements of the layer. This distance between the center of each metal wire element of the layer and the main axis is equal to half the helix diameter Dh. On the contrary, when a double helix cable extends in a substantially rectilinear direction, the distance between the center of each metal wire element of the layer and the substantially rectilinear direction is different for all the metal wire elements of the layer.

The cable according to the invention has no central metal core. Reference is also made to a 1×N structure cable in which N is the number of metallic wire elements or even an open-structure cable (“open-cord” in English). In the cable according to the invention defined above, the internal vault is empty and therefore devoid of any filling material, in particular devoid of any elastomeric composition. This is then referred to as a cable devoid of filler material.

The arch of the cable according to the invention is delimited by the metal wire elements and corresponds to the volume delimited by a theoretical circle, on the one hand, radially inside each metal wire element and, on the other hand, tangent to each metal wire element. . The diameter of this theoretical circle is equal to the arch diameter Dv.

By wire element is meant an element extending longitudinally along a main axis and having a section perpendicular to the main axis, the largest dimension G of which is relatively small compared to the dimension L along the main axis. By relatively low, it is meant that L/G is greater than or equal to 100, preferably greater than or equal to 1000. This definition covers both wireframe elements of circular section and wireframe elements of non-circular section, for example of polygonal or oblong section. Very preferably, each metal wire element has a circular section.

By metallic, we mean by definition a wire element consisting mainly (that is to say for more than 50% of its mass) or entirely (for 100% of its mass) of a metallic material. Each metal wire element is preferably made of steel, more preferably of pearlitic or ferrito-pearlitic carbon steel, commonly called by those skilled in the art carbon steel, or even stainless steel (by definition, steel comprising at least 10.5% of chromium).

The cable is manufactured in accordance with a process and by implementing an installation described in the documents WO2016083265 and WO2016083267 . Such a method implementing a splitting step is to be distinguished from a conventional wiring method comprising a single assembly step in which the metallic wire elements are wound helically, the assembly step being preceded by a step individual preforming of each metallic wire element in order in particular to increase the value of the structural elongation. Such processes and installations are described in the documents EP0548539 , EP1000194 , EP0622489 , WO2012055677 , JP2007092259 , WO2007128335 , JPH06346386 or EP0143767 . During these processes, in order to obtain the highest possible structural elongation, the metallic monofilaments are individually preformed. However, this step of individual preformation of the metal monofilaments, which requires a particular installation, on the one hand, makes the method relatively unproductive compared to a method devoid of individual preformation step without however making it possible to achieve structural elongations high and, on the other hand, alters the metal monofilaments thus preformed due to friction with the preforming tools. Such an alteration creates incipient fractures at the surface of the metal monofilaments and is therefore harmful for the endurance of the metal monofilaments, in particular for their endurance under compression. The absence or presence of such preformation marks can be observed under an electron microscope at the end of the manufacturing process, or even more simply, by knowing the manufacturing process of the cable.

Due to the process used, each metallic wire element of the cable is devoid of any pre-forming marks. Such preformation marks include in particular flats. The preformation marks also include cracks extending in section planes substantially perpendicular to the main axis along which each metallic wire element extends. Such cracks extend, in a section plane substantially perpendicular to the main axis, from a radially outer surface of each metal wire element radially towards inside each metal wireframe. As described above, such cracks are initiated by mechanical preforming tools due to bending forces, i.e. perpendicular to the main axis of each metallic wire element, which makes them very harmful for endurance. Conversely, in the process described in WO2016083265 and WO2016083267 in which the metal wire elements are preformed collectively and simultaneously on a transient core, the preformation forces are exerted in torsion and therefore not perpendicular to the main axis of each metal wire element. Any cracks created do not extend radially from the radially outer surface of each metal wire element radially towards the inside of each metal wire element but along the radially outer surface of each metal wire element which makes them not very harmful for endurance.

Any interval of values designated by the expression "between a and b" represents the range of values going from more than a to less than b (i.e. limits a and b excluded) while any interval of values designated by the expression “from a to b” means the range of values going from a to b (that is to say including the strict limits a and b).

The optional features described below may be combined with each other to the extent that such combinations are technically compatible.

Advantageously, 6 GPa≤M ₁ , preferably 8 GPa≤M ₁ . Thus, the cable takes up relatively large forces without running the risk of reaching too quickly the range of elongations corresponding to the much higher modulus M ₂ .

Advantageously, M ₁ ≤ 14 GPa, preferably M ₁ ≤ 12 GPa. Thus, the noise emitted by the tire is further reduced.

Advantageously, 65 GPa≤M ₂ , preferably 80 GPa≤M ₂ and more preferably 90 GPa≤M2. Thus, the hooping capacity of the cable is further improved.

Advantageously, M ₂ ≤ 150 GPa, preferably M ₂ ≤ 140 GPa and more preferably M ₂ ≤ 130 GPa. Thus, the risk of damage to the cable in the event of significant imposed deformation is reduced.

Advantageously, 6≤M ₂ /M ₁ , preferably 8≤M ₂ /M ₁ and more preferably 10≤M ₂ /M ₁ . This further promotes the reduction of the noise emitted by the tire and the shrinking capacity of the cable.

Advantageously, M ₂ /M ₁ ≤ 19, preferably M ₂ /M ₁ ≤ 17 and more preferably M ₂ /M ₁ ≤ 15. Thus, one avoids having, at a given modulus M ₁ , an excessively high modulus M ₂ or at modulus M ₂ given module, a modulus M ₁ too low.

Advantageously, M ₁ =20/A ₂₀₀ with A ₂₀₀ being the elongation, expressed in %, of the cable under a force of 200 MPa is such that 5 GPa ≤ M ₁ ≤ 16 GPa.

Advantageously, 6 GPa≤M _1′ , preferably 8 GPa≤M _1′ .

Advantageously, M ₁ ≤ 14 GPa, preferably M ₁ ≤ 12 GPa.

The advantageous characteristics relating to M ₁ , described above make it possible to ensure that the cable has a relatively low modulus even for all the stresses below 200 MPa. Thus, the tire emits relatively low noise over an even greater range of stresses and therefore for varied uses.

Even more advantageously, M _{1 "} =30/A ₃₀₀ with A ₃₀₀ being the elongation, expressed in %, of the cable under a force of 300 MPa is such that 5 GPa ≤ M ₁ ≤ 16 GPa.

Advantageously, 6 GPa≤M ₁ , preferably 8 GPa≤M ₁ .

Advantageously, M _1" ≤ 14 GPa, preferably M _1" ≤ 12 GPa.

The advantageous characteristics relating to M _1" described above make it possible to ensure that the cable has a relatively low modulus even for all stresses below 300 MPa. Thus, the tire emits relatively low noise over a very low range. great stress and therefore for very varied uses.

Advantageously, the cable has a structural elongation As such that As ≥ 1%, preferably As ≥ 2.5%, more preferably As ≥ 3% and even more preferably 3% ≤ As ≤ 5.5%, the structural elongation As being determined by applying standard ASTM D2969-04 of 2014 to the cable so as to obtain a force-elongation curve, the structural elongation As being equal to the elongation, in %, corresponding to the maximum slope of the force-elongation curve .

Advantageously, each metal wire element is devoid of preformation marks. In other words, the cable is obtained by a method devoid of individual preforming steps for each of the metallic wire elements.

As described above, the cable according to the invention is manufactured in accordance with a method and by implementing an installation described in the documents WO2016083265 and WO2016083267 . This method comprises a step of assembling by twisting a transitional assembly comprising M metal wire elements during which the M metal reinforcing elements are collectively and simultaneously preformed on a transitional core, then a step of separating the transitional assembly between the transient core and the cable according to the invention during which the transient assembly is separated between the transient core and at least a part of the M metallic wire elements of the transient assembly to form the cable according to the invention. More specifically, such a method comprises a step of assembling M metal wire elements together in a layer of the M metal wire elements around a transient core to form a transient assembly, and a step of splitting the transient assembly into at least first and second assemblies of M1 metal wire elements and M2 metal wire elements. At least one of the first and second assemblies then forms the cable according to the invention, that is to say that M1=N and/or M2=N.

Due to the springback of each metal wire element in response to the twisting step, the pitch of each metal wire element of the transient assembly changes from a transient pitch to the pitch P which is greater than it. A person skilled in the art will know how to determine which transitional pitch to apply in order to obtain the desired pitch P.

Similarly, the helix diameter Dh of each metallic wire element in the cable is substantially greater than the transient helix diameter of each wire element in the transient assembly, due to springback. The helix diameter Dh of each metallic wire element in the cable is all the more greater than the transient helix diameter of each wire element in the transient assembly as the twist rate is high. A person skilled in the art will know how to determine which transient helix diameter to apply in order to obtain the desired helix diameter Dh, and this according to the twist rate and the nature of the transient core. The same is true for the arch diameter Dv.

Advantageously, in a first embodiment, the step of splitting the transient assembly comprises a step of separating the transient core from the first and second assemblies. In this embodiment, the first assembly consists of M1 metallic wire elements wound together and distributed in a single layer around the axis of the first assembly. Similarly, the second assembly of this embodiment consists of M2 metallic wire elements wound together and distributed in a single layer around the axis of the second assembly. In other words, in this first embodiment, the transient core comprising at least one wire element, each wire element of the transient core does not belong to the first and second assemblies of M1 metal wire elements and M2 metal wire elements. So we have M1+M2=M.

In a first preferred variant of this first embodiment, during the splitting step, the first assembly is separated from a transient assembly formed by the second assembly and the transient core, then the second assembly and the transient core are separated. each other. In a second variant, during the splitting step, the transient core, the first assembly and the second assembly are simultaneously separated from each other in pairs.

• on récupère le noyau transitoire en aval de l'étape de fractionnement, et
• on introduit le noyau transitoire récupéré précédemment en amont de l'étape d'assemblage.

Advantageously, the method comprises a step of recycling the core transient during which:

• the transient nucleus is recovered downstream of the fractionation step, and
• the transient core recovered previously is introduced upstream of the assembly step.

In a preferred embodiment, the transient core recycling step can be carried out continuously, that is to say in which the transient core exiting from the transient core is reintroduced, without an intermediate storage step of the transient core. separation step, in the assembly step. In another embodiment, the step of recycling the transient core is discontinuous, that is to say with a step of intermediate storage of the transient core.

More preferably, a transitional textile core is used.

In a second embodiment, the step of splitting the transient assembly comprises a step of splitting the transient core between at least the first and second assemblies. Thus, in this second embodiment, two assemblies of metal wire elements are obtained, each comprising a layer of P1, P2, respectively, metal wire elements wound together in a helix, and for at least one of the assemblies, a central core comprising or consisting of at least a part of the transient core around which the metal wire elements of the layer are wound. In other words, in this second embodiment, the transitional core comprising K metal wire element(s), at least one of the K metal wire element(s) of the transient core belongs to at least one of the first and second assemblies of M1 metal wire elements and M2 metal wire elements.

Advantageously, during the splitting step, at least a first part of the transient core is split with first metallic wire elements of the transient assembly so as to form the first assembly.

Thus, the first assembly comprises a layer of P1 metal wire elements wound together helically and a central core comprising or consisting of a first part (K1 wire element(s)) of the K metal wire elements of the transient core and around which are wound together in a helix the metallic wire elements P1. We have P1+K1=M1.

Advantageously, during the splitting step, at least a second part of the transient core is split with second metallic wire elements of the transient assembly so as to form the second assembly.

Thus, the second assembly comprises a layer of P2 metallic wire elements wound together in a helix and a central core comprising or consisting by a second part (K2 wire element(s)) of the K wire elements of the transient core and around which the P2 metal wire elements are wound together in a helix. We have P2+K2=M2.

Preferably, the first and second assemblies are formed simultaneously.

Preferably, before the splitting step, the first and second parts of the transient core constitute the transient core. Thus, the first and second parts of the transient kernel are complementary. So we have K1+K2=K. Alternatively, we could have K1+K2<K.

In a variant, the first assembly comprises a layer of P1 metal wire elements wound together in a helix around a central core comprising or constituted by the transitional core and the second assembly comprises a layer of P2=M2 metal wire elements wound together in a helix and devoid of a central core.

In one embodiment, the assembly step is carried out by twisting. In such a case, the metal wire elements undergo both collective torsion and individual torsion about their own axis, which generates an untwisting torque on each of the metal wire elements. In another embodiment, the assembly step is carried out by wiring. In this case, the metallic wire elements do not undergo twisting around their own axis, due to synchronous rotation before and after the assembly point.

Preferably, in the case of an assembly step by twisting, the method comprises a step of balancing the transitional assembly. Thus, the balancing step being carried out on the assembly consisting of the M metal wire elements and the transient core, the balancing step is implicitly carried out upstream of the splitting step.

Advantageously, the method includes a step of balancing at least one of the first and second assemblies after the splitting step.

Advantageously, the method includes a step of maintaining the rotation of the first and second assemblies around their respective running direction. This step is carried out after the splitting step and before the step of balancing at least one of the first and second assemblies.

In one embodiment, the metal wire elements defining an internal vault of the cable of diameter Dv, each metal wire element having a diameter Df and a helix radius of curvature Rf, Dv, Df and Rf being expressed in millimeters, the cable satisfying the following relationships: 9 ≤ Rf / Df ≤ 30, and 1.30 ≤ Dv / Df ≤ 2.10.

Such characteristics make it possible to obtain a cable having a module M ₁ in accordance with the invention, making it possible to reduce the noise emitted by the tire while maintaining a relatively small diameter.

On the one hand, the inventors at the origin of the invention hypothesize that, due to a sufficiently high radius of curvature Rf with respect to the diameter Df of each metal wire element, the cable is sufficiently ventilated due to the relatively large distance of each metal wire element from the longitudinal axis of the cable, this distance allowing the metal wire elements to gradually approach each other and making it possible to obtain a relatively low modulus M ₁ . On the other hand, for a radius of curvature Rf of each metal wire element that is too high, the cable would have insufficient longitudinal rigidity in compression to ensure a role of reinforcement, for example of tires.

In addition, for an internal vault diameter Dv that is too high, the cable would have, relative to the diameter of the metallic wire elements, a diameter that is too high. Conversely, for an internal arch diameter Dv that is too small, the cable would have too little space between the metallic wire elements for the latter to be able to accommodate the stresses. The modulus M ₁ would then be too high and the tire too noisy.

Furthermore, for such ratios of Rf/Df and Dv/Df, the cable has excellent longitudinal compressibility giving it particularly high compression endurance.

In preferred embodiments, 11 ≤ Rf / Df ≤ 19.

In preferred embodiments, 1.30≤Dv/Df≤2.05 and more preferably 1.30≤Dv/Df≤2.00.

Advantageously, the helix radius of curvature Rf is such that 2 mm≤Rf≤7 mm.

In one embodiment of a cable intended for the reinforcement of a tire for passenger vehicles, but also for two-wheeled vehicles such as motorcycles, and preferably for passenger vehicles, we have 2 mm ≤ Rf ≤ 5 mm and preferably 3 mm ≤ Rf ≤ 5 mm.

4 mm ≤ Rf ≤ 6 mm and preferably 4 mm ≤ Rf ≤ 5 mm.

In one embodiment of a cable intended for the reinforcement of a tire for off-road vehicles, for example agricultural or civil engineering machinery, we have 4 mm ≤ Rf ≤ 7 mm and preferably 4.5 mm ≤ Rf ≤ 6.5mm.

Advantageously, the helix diameter Dh of each metallic wire element is such that 0.40 mm≤Dh≤1.50 mm.

In one embodiment of a cable intended for the reinforcement of a tire for passenger vehicles, but also for two-wheeled vehicles such as motorcycles, and preferably for passenger vehicles, we have 0.50 mm ≤ Dh ≤ 1.00 mm and preferably 0.70 mm ≤ Dh ≤ 1.00 mm.

0 .85 mm≤Dh≤1.20 mm and preferably 0.90 mm≤Dh≤1.15 mm.

In one embodiment of a cable intended for reinforcing a tire for off-road vehicles, for example agricultural or civil engineering machinery, 0.95 mm≤Dh≤1.40 mm and preferably 1.00mm ≤ Dh ≤ 1.35mm.

Advantageously, Dv is such that Dv≥0.46 mm.

In one embodiment of a cable intended for the reinforcement of a tire for passenger vehicles, but also for two-wheeled vehicles such as motorcycles, and preferably for passenger vehicles, we have 0.46 mm ≤ Dv ≤ 0.70mm.

0 .50mm ≤ Dv ≤ 0.80mm.

In one embodiment of a cord intended for the reinforcement of a tire for off-road vehicles, for example agricultural or civil engineering machinery, we have 0.55 mm≤Dv≤1.00 mm.

In preferred embodiments, each metal wire element is wound at a pitch P such that 3mm≤P≤15mm and preferably 3mm≤P≤9mm.

In one embodiment of a cable intended for the reinforcement of a tire for passenger vehicles, but also for two-wheeled vehicles such as motorcycles, and preferably for passenger vehicles, we have 3 mm ≤ P ≤ 9 mm .

7 mm ≤ D ≤ 15mm.

In one embodiment of a cable intended for the reinforcement of a tire for off-road vehicles, for example agricultural or civil engineering machinery, we have 9 mm ≤ P ≤ 15 mm.

In an advantageous embodiment, all the metallic wire elements have the same diameter Df.

Advantageously, Df is such that 0.10 mm≤Df≤0.50 mm.

In one embodiment of a cable intended for the reinforcement of a tire for passenger vehicles, but also for two-wheeled vehicles such as motorcycles, and preferably for passenger vehicles, we have 0.20 mm ≤ Df ≤ 0.35 mm and preferably 0.25 mm ≤ Df ≤ 0.33 mm.

0 .22 mm ≤ Df ≤ 0.40 mm and preferably 0.25 mm ≤ Df ≤ 0.38 mm.

In one embodiment of a cord intended for reinforcing a tire for off-road vehicles, for example agricultural or civil engineering machinery, 0.32 mm≤Df≤0.50 mm and preferably 0.35mm≤Df≤0.50mm.

Advantageously, the cable has a diameter D such that D≤2.00 mm.

The diameter or apparent diameter, denoted D, is measured by means of a thickness comparator whose diameter of the keys is at least equal to 1.5 times the pitch P of winding of the wire elements (one can cite for example the model JD50 of the KAEFER brand allowing an accuracy of 1/100 of a millimeter to be achieved, equipped with a type a key, and having a contact pressure close to 0.6N). The measurement protocol consists of three repetitions of a series of three measurements (carried out perpendicular to the axis of the cable and under zero tension) of which the second and third of these measurements are carried out in a direction angularly offset from the previous one by a third of a turn, by the rotation of the direction of measurement around the axis of the cable.

In one embodiment of a cable intended for the reinforcement of a tire for passenger vehicles, but also for two-wheeled vehicles such as motorcycles, and preferably for passenger vehicles, we have 0.75 mm≤D≤ 1.40 mm and preferably 1.00 mm≤D≤1.30 mm.

1 .15mm ≤ D ≤ 1.55mm.

In one embodiment of a cable intended for the reinforcement of a tire for off-road vehicles, for example agricultural or engineering machinery civilian, we have 1.5 mm ≤ D ≤ 2 mm.

In one embodiment, each metal wireframe includes a single metal monofilament. Here, each metallic wire element advantageously consists of a metallic monofilament. In a variant of this embodiment, the metallic monofilament is directly coated with a layer of a metallic coating comprising copper, zinc, tin, cobalt or an alloy of these metals, for example brass or the bronze. In this variant, each metal wire element then consists of the metal monofilament, for example steel, forming a core, directly coated with the metal coating layer.

In this embodiment, each metallic elementary monofilament is, as described above, preferably made of steel, and has a mechanical strength ranging from 1000 MPa to 5000 MPa. Such mechanical strengths correspond to the steel grades commonly encountered in the field of tires, namely, NT (Normal Tensile), HT (High Tensile), ST (Super Tensile), SHT (Super High Tensile), UT ( Ultra Tensile), UHT (Ultra High Tensile) and MT (Mega Tensile), the use of high mechanical strength possibly allowing improved reinforcement of the matrix in which the cable is intended to be embedded and a lightening of the matrix thus reinforced.

Advantageously, the layer being made up of N metal wire elements wound in a helix, N ranges from 3 to 6.

Advantageously, the ratio K of the pitch P to the diameter Df of each metal wire element, P and Df being expressed in millimeters, is such that 19≤K≤44.

Advantageously, the helix angle α of each metallic wire element is such that 13°≤α≤21°.

For too high values of the ratio K or for too low helix angle values, the longitudinal compressibility of the cable is reduced and the tire too noisy. For values of the ratio K that are too low or for values of the helix angle that are too high, the longitudinal stiffness of the cable and therefore its capacity for reinforcement are reduced.

FILLED CABLE ACCORDING TO THE INVENTION

• 5 GPa ≤ M_c1 ≤ 30 GPa, et
• 40 GPa ≤ M_c2 ≤ 150 GPa, et
• 3 ≤ M_c2/M_c1,

M_c1 et M_c2 étant exprimés en GPa avec :

• M_c1=10 / A_c100 avec :
  • A_c100 étant l'allongement, exprimé en %, du câble rempli sous un effort de 100 MPa, et
• M_c2=[(F_c40-F_c30) / (A_c40-A_c30)] / S avec :
  • S étant la section, exprimée en mm², telle que S=MI /Mv avec :
    • ▪ MI étant la masse linéique des éléments filaires métalliques, exprimée en g par m de câble,
    • ▪ Mv étant la masse volumique des éléments filaires métalliques, exprimée en g par cm³,
  • F_c40 étant la force, exprimée en daN, égale à 40 % de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,
  • F_c30 étant la force, exprimée en daN, égale à 30 % de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,
  • A_c40 étant l'allongement du câble rempli, exprimé en %, à 40% de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,
  • A_c30 étant l'allongement du câble rempli, exprimé en %, à 30% de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,
  avec F_ct=MI x Rm / Mv, exprimée en daN, avec Rm étant la résistance mécanique à rupture moyenne, exprimée en MPa, des éléments filaires métalliques constituant la couche unique.

The invention also relates to a filled cable comprising a single layer of metal wire elements wound in a helix, each metal wire element of the layer describing, when the cable extends in a substantially rectilinear direction, a trajectory in the form of an helix around a principal axis substantially parallel to the substantially rectilinear direction, so that, in a section plane substantially perpendicular to the main axis, the distance between the center of each metal wire element of the layer and the main axis is substantially constant and equal for all the metal wire elements of the layer, the metal wire elements defining an internal arch of the cable , the filled cable comprising a filling material of the internal arch based on an elastomeric composition and located in the internal arch of the filled cable, filled cable in which:

• 5 GPa ≤ M _c1 ≤ 30 GPa, and
• 40 GPa ≤ M _c2 ≤ 150 GPa, and
• 3 ≤ M _c2 /M _c1,

M _c1 and M _c2 being expressed in GPa with:

• M _c1 =10 / A _c100 with:
  • A _c100 being the elongation, expressed in %, of the cable filled under a force of 100 MPa, and
• M _c2 =[(F _c40 -F _c30 ) / (A _c40 -A _c30 )] / S with:
  • S being the section, expressed in mm ² , such that S=MI /Mv with:
    • ▪ MI being the linear mass of the metallic wire elements, expressed in g per m of cable,
    • ▪ Mv being the density of the metallic wire elements, expressed in g per cm ³ ,
  • F _c40 being the force, expressed in daN, equal to 40% of the maximum theoretical force F _ct of the cable without filling material,
  • F _c30 being the force, expressed in daN, equal to 30% of the maximum theoretical force F _ct of the cable without filling material,
  • A _c40 being the elongation of the filled cable, expressed in %, at 40% of the maximum theoretical force F _ct of the cable without the filling material,
  • A _c30 being the elongation of the filled cable, expressed in %, at 30% of the maximum theoretical force F _ct of the cable without filling material,
  with F _ct =MI x Rm / Mv, expressed in daN, with Rm being the mechanical strength at average rupture, expressed in MPa, of the metallic wire elements constituting the single layer.

The filled cable according to the invention is obtained by embedding in an elastomeric matrix a cable devoid of filling material as defined above. The elastomeric matrix is based on an elastomeric composition. The filling material is based on an elastomeric composition, here the same composition as that of the matrix in which the filled cable is embedded.

The vault of the cable devoid of filler material or of the cable filled according to the invention is delimited by the metal wire elements and corresponds to the volume delimited by a theoretical circle, on the one hand, radially inside each metal wire element and, on the other hand, tangent to each metal wire element.

Due to the presence of the filling material, the filled cable has a higher modulus M _c1 than the modulus M ₁ of the cable without the filling material. Indeed, for relatively low forces, the filler material prevents the radial approximation of the metal wire elements of the single layer, then generating an increase in the modulus M _c1 compared to the modulus M ₁ of a cable devoid of the filler material and in which nothing prevents the radial approximation of the metallic wire elements of the single layer.

Due to the presence of the filling material, the filled cable has a lower modulus M _c2 than the modulus M ₂ of the cable without the filling material. Indeed, for relatively large efforts, the filler material having fixed the position of the wire elements relative to each other, the wire elements of the filled cable are stressed while they have a greater helix angle than the elements cords of the cable without filler material. This greater helix angle value of the wire elements of the filled cable then causes a drop in the modulus M _c2 relative to the modulus M ₂ of the cable devoid of the filling material.

By elastomeric matrix is meant a matrix with elastomeric behavior resulting from the crosslinking of an elastomeric composition. The elastomeric matrix is thus based on the elastomeric composition. Like the elastomeric matrix, the filling material is based on an elastomeric composition, here the same composition as that of the matrix in which the cable is embedded.

The expression "based on" should be understood to mean that the composition comprises the mixture and/or the in situ reaction product of the various constituents used, some of these constituents being able to react and/or being intended to react with one another, less partially, during the various phases of manufacture of the composition; the composition thus possibly being in the totally or partially crosslinked state or in the non-crosslinked state.

By elastomeric composition, it is meant that the composition comprises at least one elastomer and at least one other component. Preferably, the composition comprising at least one elastomer and at least one other component comprises an elastomer, a crosslinking system and a filler. The compositions used for these sheets are conventional compositions for calendering filamentary reinforcing elements, comprise a diene elastomer, for example natural rubber, a reinforcing filler, for example carbon black and/or silica, a crosslinking, for example a vulcanization system, preferably comprising sulfur, stearic acid and zinc oxide, and optionally a vulcanization accelerator and/or retarder and/or various additives. The adhesion between the reinforcing wire elements and the matrix in which they are embedded is ensured for example by a usual adhesive composition, for example an adhesive of the RFL type or equivalent adhesive.

As for the cable devoid of filling material, M ₁ is representative of the modulus of the cable for the forces undergone by the cable during rolling under normal conditions and therefore representative of the conditions under which the so-called "coast-by" noise is emitted. and M ₂ is representative of the modulus of the cable for the forces undergone by the cable during when strong stresses are exerted on the tire.

The values of A _c30 and A _c40 are obtained by determining, on a force-elongation curve obtained by pulling a cable filled under the conditions of standard ASTM D2969-04 of 2014, respectively the values at 30% and 40% of the force theoretical maximum F _ct of the cable without filler material. In view of the foregoing, F _ct is equal to F _t because F _t . Analogously to the value A ₁₀₀ , the value of A _c100 is obtained by determining, on a force-elongation curve obtained by pulling a filled cable under the conditions of standard ASTM D2969-04 of 2014, the elongation of the filled cable under a force of 100 MPa.

The average breaking strength Rm of the metal wire elements of the filled cable is identical to the average breaking strength Rm of the metal wire elements of the cable devoid of filling material. The linear masses MI and density Mv of the filled cable are, by definition, identical respectively to the linear masses MI and density Mv of the cable without filler material.

The values of the characteristics M _c1 , M _c2 , M _c2 /M _c1 , M _c1' , M _c1" , F _nt , MI, Mv, Rm as well as the other characteristics described below are measured on or determined from cables extracted from an elastomeric matrix, for example from a tire and in which the filler material is kept.

The cable filled according to the invention is manufactured like the cable according to the invention devoid of filling material according to a process and by implementing an installation described in the documents WO2016083265 and WO2016083267 .

The optional features described below may be combined with each other to the extent that such combinations are technically compatible.

Advantageously, 7 GPa≤M _c1 , preferably 10 GPa≤M _c1 . Thus, the filled cable takes up relatively high forces without running the risk of reaching too quickly the range of elongations corresponding to the much higher modulus M _c2 .

Advantageously, M _c1 ≤ 25 GPa, preferably M _c1 ≤ 20 GPa. Thus, the noise emitted by the tire is further reduced.

Advantageously, 60 GPa≤M _c2 , preferably 70 GPa≤M _c2 and more preferably 80 GPa≤M _c2 . Thus, the hooping capacity of the cable is further improved.

Advantageously, M _c2 ≤ 140 GPa, preferably M _c2 ≤ 130 GPa and more preferably M _c2 ≤ 120 GPa. Thus, the risk of damage to the filled cable in the event of significant imposed deformation is reduced.

Advantageously, 4≤M _c2 /M _c1 , preferably 5≤M _c2 /M _c1 , and more preferably 6≤M _c2 /M _c1 . This further promotes the reduction of the noise emitted by the tire and the shrinking capacity of the filled cable.

Advantageously, M _c2 /M _c1 ≤ 12, preferably M _c2 /M _c1 ≤ 11 and more preferably M _c2 /M _c1 ≤ 10. This avoids having, at a given modulus M _c1 , an excessively high modulus M _c2 or at a given modulus M _c2 module, a modulus M _c1 that is too low.

Advantageously, M _{c1′ =} 20/A _c200 with A _c200 being the elongation, expressed in %, of the cable filled under a force of 200 MPa is such that 5 GPa≤M c1′≤30 GPa.

Advantageously, 7 GPa ≤ M _c1' , preferably 10 GPa ≤ M _c1' ,

Advantageously, M _c1′≤25 GPa, preferably M _c1′≤20 GPa.

The advantageous characteristics relating to M _c1' described above make it possible to ensure that the filled cable has a relatively low modulus even for all the stresses below 200 MPa. Thus, the tire emits relatively low noise over an even greater range of stresses and therefore for varied uses.

Advantageously, M _c1″ =30/A _c300 with A _c300 being the elongation, expressed in %, of the cable filled under a force of 300 MPa is such that 5 GPa≤M _c1″ ≤30 GPa.

Advantageously, 7 GPa ≤ M _c1" , preferably 10 GPa ≤ M _c1" .

Advantageously, M _c1″ ≤25 GPa, preferably M _c1″ ≤20 GPa.

The advantageous characteristics relating to M _c1" described above make it possible to ensure that the filled cord has a relatively low modulus even for all stresses below 300 MPa. Thus, the tire emits relatively low noise over a range great stress and therefore for very varied uses.

Advantageously, the filled cable has a structural elongation Asc such that Asc ≥ 1%, preferably Asc ≥ 1.5%, more preferably Asc ≥ 2% and even more preferably 2% ≤ Asc ≤ 4%, the structural elongation Asc being determined by applying ASTM D2969-04 of 2014 to the filled cable so as to obtain a force-elongation curve, the structural elongation Asc being equal to the elongation, in %, corresponding to the maximum slope of the force-elongation curve.

OTHER OBJECTS ACCORDING TO THE INVENTION

The invention also relates to the use of a cable devoid of filling material or of a filled cable as defined above for the reinforcement of articles or semi-finished products comprising an elastomeric matrix in which is embedded the cable.

Such articles or semi-finished products are pipes, belts, conveyor belts, caterpillars, tires for vehicles, both in the raw state (that is to say before cross-linking or vulcanization) and in the cured state (after cross-linking or vulcanization). Such articles or semi-finished products take, in preferred modes, the form of a sheet.

The invention also relates to an article or semi-finished product comprising an elastomeric matrix in which is embedded at least one filled cable as defined above.

Another object of the invention is the use of a cord devoid of filler material or of a filled cord as defined above for reinforcing a tire comprising the cord.

Within the article or semi-finished product according to the invention, for example within the tires according to the invention, the filled cable is embedded in an elastomeric matrix. Within the article or semi-finished product according to the invention, for example within the tires according to the invention, the filled cord comprises a filling material for the internal arch based on an elastomeric composition and located in the internal cable vault filled. The filling material here is based on the same elastomeric composition as that based on the elastomeric matrix in which the cable is embedded.

TIRES ACCORDING TO THE INVENTION

• l'armature de sommet comprenant une armature de frettage comprenant au moins une nappe de frettage comprenant au moins un élément filaire de renfort de frettage noyé dans une matrice élastomérique à base d'une composition élastomérique et une armature de travail comprenant au moins une nappe de travail comprenant des éléments filaires de renfort de travail,
• l'armature de carcasse comprenant au moins une nappe de carcasse comprenant des éléments filaires de renfort de carcasse,
• au moins les éléments filaires de renfort de travail et les éléments filaires de renfort de carcasse étant agencés de façon à définir, en projection sur le plan circonférentiel équatorial selon la direction radiale du pneumatique, un maillage triangulaire, le ou chaque élément filaire de renfort de frettage est constitué par un câble rempli comprenant une unique couche d'éléments filaires métalliques enroulés en hélice, les éléments filaires métalliques définissant une voûte interne du câble rempli, le câble rempli comprenant un matériau de remplissage de la voûte interne à base de la composition élastomérique et située dans la voûte interne du câble rempli, le câble rempli étant, après extraction du pneumatique, tel que défini ci-dessus.

Another object of the invention is a tire comprising a crown comprising a tread and a crown reinforcement, two sidewalls, two beads, each sidewall connecting each bead to the crown, the crown reinforcement extending into the crown along a circumferential direction of the tire, the tire comprising a carcass reinforcement anchored in each of the beads and extending in the sidewalls and in the crown, the crown reinforcement being radially interposed between the carcass reinforcement and the tread,

• the crown reinforcement comprising a hooping reinforcement comprising at least one hooping ply comprising at least one wired hooping reinforcement element embedded in an elastomeric matrix based on an elastomeric composition and a working reinforcement comprising at least one ply of work comprising work reinforcing wire elements,
• the carcass reinforcement comprising at least one carcass ply comprising corded carcass reinforcement elements,
• at least the wired work reinforcement elements and the wired carcass reinforcement elements being arranged so as to define, in projection on the equatorial circumferential plane in the radial direction of the tire, a triangular mesh, the or each wired work reinforcement element hooping is constituted by a filled cable comprising a single layer of metal wire elements wound in a helix, the metal wire elements defining an internal arch of the filled cable, the filled cable comprising a filling material of the internal arch based on the elastomeric composition and located in the inner vault of the filled cable, the filled cable being, after extraction from the tire, as defined above.

The tire defined here uses the characteristics of the filled cord defined above in order to reduce the noise emitted and to present an efficient hooping reinforcement. A person skilled in the art will choose the dimensional characteristics of the cord and the density of cords in the hooping ply according to the desired use of the tire. Thus, the tires of the invention may be intended for passenger motor vehicles (including in particular 4x4 vehicles and "SUVs" (Sport Utility Vehicles)), but also for two-wheeled vehicles such as motorcycles, or for industrial vehicles chosen from vans, "Heavyweight" - i.e., metro, bus, road transport vehicles (trucks, tractors, trailers), off-road vehicles -, agricultural or civil engineering vehicles, planes, other vehicles transportation or handling.

The advantageous and optional characteristics described above with reference to the filled cable also apply to the tire defined above.

• 100 daN.mm^-1 ≤ M_n1 ≤ 600 daN.mm^-1, et
• 1000 daN.mm^-1 ≤ M_n2 ≤ 4500 daN.mm^-1, et
• 3 ≤ M_n2/M_n1,

M_n1 et M_n2 étant exprimés en daN.mm^-1 avec

• M_n1=250 / A_n250 avec :
  • A_n250 étant l'allongement équivalent, exprimé en %, de la nappe de frettage sous un effort de 250 daN.dm^-1, A_n250 étant obtenu en divisant l'effort de 250 daN.dm^-1 par la densité d'éléments filaires de renfort de frettage par décimètre de nappe de frettage de façon à obtenir un effort unitaire, puis, en déterminant sur une courbe force-allongement obtenue en tractionnant le câble rempli dans les conditions de la norme ASTM D2969-04 de 2014, l'allongement du câble rempli sous cet effort unitaire, et
• M_n2=[(F_n40-F_n30) / (A_n40-A_n30)] avec :
  • F_n40 étant la force, exprimée en daN.dm^-1, égale à 40 % de la force théorique maximale F_nt de la nappe de frettage,
  • F_n30 étant la force, exprimée en daN.dm^-1, égale à 30 % de la force théorique maximale F_nt de la nappe de frettage,
  • A_n40 étant l'allongement équivalent de la nappe de frettage, exprimé en %, à 40% de la force théorique maximale F_nt de la nappe de frettage, A_n40 étant obtenu en divisant 40% de la force théorique maximale F_nt de la nappe de frettage par la densité d d'éléments filaires de renfort de frettage par décimètre de nappe de frettage de façon à obtenir un effort unitaire à 40%, puis en déterminant sur une courbe force-allongement obtenue en tractionnant le câble rempli dans les conditions de la norme ASTM D2969-04 de 2014, l'allongement du câble rempli sous cet effort unitaire,
  • A_n30 étant l'allongement équivalent de la nappe de frettage, exprimé en %, à 30% de la force théorique maximale F_nt de la nappe de frettage, A_n30 étant obtenu en divisant 30% de la force théorique maximale F_nt de la nappe de frettage par la densité d d'éléments filaires de renfort de frettage par décimètre de nappe de frettage de façon à obtenir un effort unitaire à 30%, puis en déterminant sur une courbe force-allongement obtenue en tractionnant le câble rempli dans les conditions de la norme ASTM D2969-04 de 2014, l'allongement du câble rempli sous cet effort unitaire,
    avec F_nt= MI × Rm × d / Mv, exprimée en daN.dm^-1, avec :
    • ▪ MI étant la masse linéique des éléments filaires métalliques, exprimée en g par m de câble,
    • ▪ Mv étant la masse volumique des éléments filaires métalliques, exprimée en g par cm³,
    • ▪ Rm étant la résistance mécanique à rupture moyenne, exprimée en MPa, des éléments filaires métalliques constituant la couche unique, et
    • ▪ d étant la densité du ou des éléments filaires de renfort de frettage dans la nappe de frettage, exprimée en nombre par dm de nappe de frettage.

Yet another object of the invention is a tire comprising a crown comprising a tread and a crown reinforcement, two sidewalls, two beads, each sidewall connecting each bead to the crown, the crown reinforcement extending into the crown in a circumferential direction of the tire, the tire comprising a carcass reinforcement anchored in each of the beads and extending in the sidewalls and in the crown, the crown reinforcement being radially interposed between the carcass reinforcement and the tread , the crown reinforcement comprising a hooping reinforcement comprising at least one hooping ply comprising at least one wired hooping reinforcement element embedded in an elastomeric matrix based on an elastomeric composition and a working reinforcement comprising at least one ply of work comprising wire-based work reinforcement elements, the carcass reinforcement comprising at least one carcass ply comprising wire-based carcass reinforcement elements, at least the wire-based work reinforcement elements and the wire-based carcass reinforcement elements being arranged so as to define, in projection on the equatorial circumferential plane in the radial direction of the tire, a triangular mesh, the or each hooping reinforcing wire element is constituted by a filled cable comprising a single layer of metallic wire elements wound in a helix , each metallic wire element of the describing layer, when the cable extends along a d substantially rectilinear direction, a trajectory in the form of a helix around a principal axis substantially parallel to the substantially rectilinear direction, so that, in a section plane substantially perpendicular to the principal axis, the distance between the center of each element metal wireframe of the layer and the main axis is substantially constant and equal for all the metal wireframe elements of the layer, the metal wireframe elements defining an internal arch of the filled cable, the filled cable comprising a filling material of the internal arch at base of the elastomeric composition and located in the internal arch of the filled cable, the hooping ply having, after extraction from the tire, the following characteristics:

• 100 daN.mm ^-1 ≤ M _n1 ≤ 600 daN.mm ^-1 , and
• 1000 daN.mm ^-1 ≤ M _n2 ≤ 4500 daN.mm ^-1 , and
• 3 ≤ M _n2 /M _n1 ,

M _n1 and M _n2 being expressed in daN.mm ^-1 with

• M _n1 =250 / A _n250 with:
  • A _n250 being the equivalent elongation, expressed in %, of the hooping ply under a force of 250 daN.dm ^-1 , A _n250 being obtained by dividing the force of 250 daN.dm ^-1 by the density of elements cords of hooping reinforcement per decimeter of hooping ply so as to obtain a unit force, then, by determining on a force-elongation curve obtained by pulling the filled cable under the conditions of standard ASTM D2969-04 of 2014, the elongation of the filled cable under this unit force, and
• M _n2 =[(F _n40 -F _n30 ) / (A _n40 -A _n30 )] with:
  • F _n40 being the force, expressed in daN.dm ^-1 , equal to 40% of the maximum theoretical force F _nt of the hooping layer,
  • F _n30 being the force, expressed in daN.dm ^-1 , equal to 30% of the maximum theoretical force F _nt of the hooping layer,
  • A _n40 being the equivalent elongation of the hooping ply, expressed in %, at 40% of the maximum theoretical force F _nt of the hooping ply, A _n40 being obtained by dividing 40% of the maximum theoretical force F _nt of the hooping ply by the density d of hooping reinforcing wire elements per decimeter of hooping ply so as to obtain a unit effort at 40%, then by determining on a force-elongation curve obtained by pulling the cable filled under the conditions of the ASTM D2969-04 standard of 2014, the elongation of the cable filled under this unit effort,
  • A _n30 being the equivalent elongation of the hooping ply, expressed in %, at 30% of the maximum theoretical force F _nt of the hooping ply, A _n30 being obtained by dividing 30% of the maximum theoretical force F _nt of the hooping ply by the density d of hooping reinforcing wire elements per decimetre of hooping ply so as to obtain a unit effort at 30%, then by determining on a force-elongation curve obtained by pulling the cable filled under the conditions of the ASTM D2969-04 standard of 2014, the elongation of the cable filled under this unit effort,
    with F _nt = MI × Rm × d / Mv, expressed in daN.dm ^-1 , with:
    • ▪ MI being the linear mass of the metallic wire elements, expressed in g per m of cable,
    • ▪ Mv being the density of the metallic wire elements, expressed in g per cm ³ ,
    • ▪ Rm being the average breaking strength, expressed in MPa, of the metallic wire elements constituting the single layer, and
    • ▪ d being the density of the hooping reinforcing wire element(s) in the hooping ply, expressed as a number per dm of hooping ply.

The tire defined here has characteristics compatible with passenger-car motor vehicles (including in particular 4×4 vehicles and “SUVs” (Sport Utility Vehicles)).

In a similar way to the cable devoid of filler material or to the filled cable, the tire according to the invention emits a relatively reduced noise due to a value of M _n1 ranging from 100 daN.mm ^-1 to 600 daN.mm ^-1 . M _n1 is representative of the modulus of the hooping ply for the forces undergone by the ply during rolling under normal conditions and therefore representative of the conditions under which the so-called “coast-by” noise is emitted.

In a manner analogous to the cord devoid of filler material or to the filled cord, the tire according to the invention has a high-performance hooping reinforcement due to a value of M _n2 ranging from 1000 daN.mm ⁻¹ to 4500 daN. mm ^-1 . M _n2 is representative of the modulus of the hooping ply for the forces undergone by the hooping ply during when strong stresses are exerted on the tire.

Finally, the ratio M _n2 /M _n1 ensures that both the lowest possible noise emitted and a high-performance hooping reinforcement are obtained and that one performance is not sacrificed in relation to another. The equivalent elongation A _n250 is determined by relating the force of 250 daN.dm ^-1 to a unit force undergone by each hooping reinforcing wire element of the hooping ply. For this, the force of 250 daN.dm ^-1 is divided by the density of hooping reinforcing wire elements per decimetre of hooping ply. We then obtain a unit effort. Then, on a force-elongation curve obtained by pulling a cord of the tire under the conditions of standard ASTM D2969-04 of 2014, the elongation of the cord of the tire under this unit force is determined. The equivalent elongation A _n250 is then obtained.

Each equivalent elongation A _n40 and A _n30 is determined in a similar way to the elongation A _n250 by relating the force at 30% or 40% of the maximum theoretical force F _nt of the hooping layer to a unit force undergone by each hooping reinforcing wire element of the ply. To do this, 30% or 40% of the maximum theoretical force F _nt of the hooping ply is divided by the density d of hooping reinforcing wire elements per decimeter of hooping ply. We then obtain a unit effort of 30% or 40%. Then, on a force-elongation curve obtained by pulling a cord of the tire under the conditions of standard ASTM D2969-04 of 2014, the elongation of the cord of the tire under this unit force is determined. The equivalent elongation A _n30 or A _n40 is then obtained.

The average breaking strength Rm of the metal cord elements of the tire cord is identical to the average breaking strength Rm of the metal cord elements of the cord devoid of filling material or of the filled cord. The linear masses MI and density Mv of the cord of the tire are, by definition, identical respectively to the linear masses MI and density Mv of the cord devoid of filler material or of the filled cord.

The density d of reinforcing wire elements in a ply is the number reinforcing wire elements present in the ply in a direction perpendicular to the direction in which the reinforcing wire elements extend in the ply. The density d can also be determined from the laying pitch p expressed in mm, the laying pitch being equal to the axis-to-axis distance between two consecutive reinforcing wire elements in the direction perpendicular to the direction in which the reinforcing elements extend into the web. The relationship between d and p is d=100/p.

The values of the characteristics M _n1 , M _n2 , M _n2 /M _n1 , M _n1' , M _n1" , F _nt , MI, Mv, Rm, d as well as the other characteristics described below are measured on or determined from plies and cables extracted from a tire.

By tire is meant a tire intended to form a cavity by cooperating with a support element, for example a rim, this cavity being capable of being pressurized to a pressure greater than atmospheric pressure. A tire according to the invention has a structure of substantially toroidal shape.

By radial section or radial section here is meant a section or a section along a plane which comprises the axis of rotation of the tire.

By axial direction is meant the direction substantially parallel to the axis of rotation of the tire.

By circumferential direction is meant the direction which is substantially perpendicular both to the axial direction and to a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire).

By radial direction is meant the direction along a radius of the tire, that is to say any direction intersecting the axis of rotation of the tire and substantially perpendicular to this axis.

The median plane (denoted M) is the plane perpendicular to the axis of rotation of the tire which is located halfway between the two beads and passes through the middle of the crown reinforcement.

The equatorial circumferential plane (denoted E) of the tire is the theoretical plane passing through the equator of the tire, perpendicular to the median plane and to the radial direction. The equator of the tire is, in a plane of circumferential section (plane perpendicular to the circumferential direction and parallel to the radial and axial directions), the axis parallel to the axis of rotation of the tire and located equidistant between the point radially outermost point of the tread intended to be in contact with the ground and the radially innermost point of the tire intended to be in contact with a support, for example a rim, the distance between these two points being equal to H.

By orientation of an angle, we mean the direction, clockwise or anti-clockwise, in which it must turn from a reference straight line, here the circumferential direction of the tire, defining the angle to reach the other straight line defining the angle.

The secant tensile modulus of a sheet for a force equal to 15% of the breaking force is denoted MA ₁₅ and is expressed in daN/mm. The MA ₁₅ modulus is calculated from a force-elongation curve obtained by applying the ASTM D2969-04 standard of 2014 to a cord of the sheet. The secant modulus in tension of the cable is calculated by determining the slope of the line drawn between the points (0,0) and the point of the curve having an ordinate equal to 15% of the breaking force. The modulus MA ₁₅ is determined by multiplying the tensile secant modulus of the cable by the density d of cables per mm of ply, this density being as defined above.

The breaking force of a cable is measured according to the ASTM D2969-04 standard of 2014. The breaking force of a sheet is calculated from a force-elongation curve obtained by applying the ASTM D2969-04 standard of 2014 to a cable from the tablecloth. The breaking force of the ply is determined by multiplying the breaking force of the cable by the density d of cables per unit width of the ply, this density being as defined above.

The optional features described below may be combined with each other to the extent that such combinations are technically compatible.

Advantageously, 125 daN.mm ^-1 ≤ M _n1 , preferably 150 daN.mm ^-1 ≤ M _n1 . Thus, the hooping ply takes up relatively high forces without running the risk of reaching too quickly the range of elongations corresponding to the much higher modulus M _n2 .

Advantageously, M _n1 ≤ 500 daN.mm ^-1 , preferably M _n1 ≤ 400 daN.mm ^-1 . Thus, the noise emitted by the tire is further reduced.

Advantageously, 1500 daN.mm ^-1 ≤ M _n2 , preferably 1750 daN.mm ^-1 ≤ M _n2 and more preferably 2000 daN.mm ^-1 ≤ M _n2 . Thus, the hooping capacity of the cable is further improved.

Advantageously, M _n2 ≤ 4000 daN.mm ^-1 , preferably M _n2 ≤ 3800 daN.mm ^-1 and M _n2 ≤ 3200 daN.mm ^-1 . Thus, the risk of damage to the hooping ply is reduced in the event of significant imposed deformation.

Advantageously, 4≤M _n2 /M _n1 , preferably 5≤M _n2 /M _n1 and more preferably 6≤M _n2 /M _n1 . This further promotes the reduction of the noise emitted by the tire and the shrinking capacity of the cable.

Advantageously, M _n2 /M _n1 ≤ 12, preferably M _n2 /M _n1 ≤ 11 and more preferably M _n2 /M _n1 ≤ _{10 .} high or at modulus M _n2 given module, a modulus M _n1 too low.

Advantageously, M _n1' =500/A _n500 with A _n500 being the equivalent elongation, expressed in %, of the hooping ply under a force of 500 daN.dm ^-1 is such that 100 daN.mm ^-1 ≤ M _n1 ' ≤ 600 daN.mm ^-1 .

Advantageously, 125 daN.mm ^-1 ≤ M _n1' , preferably 150 daN.mm ^-1 ≤ M _n1' ,

Advantageously, M _n1′≤500 daN.mm ⁻¹ , preferably M _n1′≤400 daN.mm ⁻¹ .

The advantageous characteristics relating to M _n1′ described above make it possible to ensure that the hooping ply has a relatively low modulus even for all stresses less than 500 daN.dm ⁻¹ . Thus, the tire emits relatively low noise over an even greater range of stresses and therefore for varied uses.

Advantageously, M _n1" =750/A _n750 with A _n750 being the equivalent elongation, expressed in %, of the hooping ply under a force of 750 daN.dm ^-1 is such that 100 daN.mm ^-1 ≤ M _{n1 "} ≤ 600 daN.mm ^-1 .

Advantageously, 125 daN.mm ^-1 ≤ M _n1" , preferably 150 daN.mm ^-1 ≤ M _n1" ,

Advantageously, M _n1" ≤ 500 daN.mm ^-1 , preferably M _n1" ≤ 400 daN.mm ^-1 .

The advantageous characteristics relating to M _n1" described above make it possible to ensure that the hooping ply has a relatively low modulus even for all stresses of less than 750 daN.dm ^-1 . Thus, the tire emits a noise relatively low over a very wide range of stresses and therefore for a wide variety of uses.

In a preferred embodiment, the filled cable is, after extraction from the tire, as defined previously. Very preferably, the filled cable is, after extraction from the tire, such that 5 GPa≤M c1≤30 GPa, 40 GPa≤M _c2≤150 GPa, and _{3≤M c2 /} M _c1 . Even more preferably, the filled cord has, after extraction from the tire, the advantageous characteristics described above relating to M _c1 , M _c2 , M _c2 /M _c1 , M _c1' and M _c1″ .

In an advantageous embodiment, the hooping reinforcement comprises a single hooping ply. Advantageously, the hooping reinforcement comprises a single hooping ply. Thus, the hooping reinforcement is, with the exception of the hooping ply, devoid of any ply reinforced by wire reinforcing elements. The wire reinforcing elements of such reinforced plies excluded from the hooping reinforcement of the tire comprise metal wire reinforcing elements and textile wire reinforcing elements. Very preferably, the hooping reinforcement consists of a hooping sheet. This embodiment is particularly suitable for a tire for passenger vehicles, two-wheeled vehicles, industrial vehicles chosen from vans, "heavy goods vehicles", for example metros, buses, transport vehicles road (trucks, tractors, trailers), and preferably for passenger vehicles.

In an advantageous embodiment, the hooping reinforcement is radially interposed between the working reinforcement and the tread. Thus, thanks to the use of metal cables, the hooping reinforcement exerts, in addition to its hooping function, a function of protection against perforations and shocks much more effective than a hooping reinforcement comprising wire elements of textile hooping reinforcement.

In an advantageous embodiment, the or each wired hooping reinforcement element makes an angle strictly less than 10°, preferably less than or equal to 7° and more preferably less than or equal to 5° with the circumferential direction of the tire.

In an advantageous embodiment, each working reinforcing wire element is a metal wire element.

In an advantageous embodiment, the wired working reinforcement elements of each working ply are arranged side by side substantially parallel to each other. More preferably, each wired working reinforcement element extends axially from one axial end of the working reinforcement of the tire to the other axial end of the working reinforcement of the tire.

In an advantageous embodiment, the carcass reinforcement comprises a single carcass ply. Thus, the carcass reinforcement is, with the exception of the carcass ply, devoid of any ply reinforced by wire reinforcing elements. The wire-like reinforcing elements of such reinforced plies excluded from the carcass reinforcement of the tire comprise metal wire-like reinforcing elements and textile wire-like reinforcing elements. Very preferably, the carcass reinforcement consists of a carcass ply. This embodiment is particularly suitable for a tire for passenger vehicles, two-wheeled vehicles, industrial vehicles chosen from vans, "heavy goods vehicles", for example metros, buses, road transport vehicles (trucks, tractors, trailers), and preferably for passenger vehicles.

In an advantageous embodiment, each carcass reinforcement wire element is a textile wire element.

The term “textile” is understood to mean by definition a non-metallic filamentary element consisting of one or more elementary textile monofilament optionally coated with one or more layers of a coating based on an adhesive composition. Each elementary textile monofilament is obtained, for example, by melt spinning, solution spinning or gel spinning. Each elementary textile monofilament is made of an organic, in particular polymeric, or inorganic material, such as glass or carbon. The polymeric materials can be of the thermoplastic type, such as for example aliphatic polyamides, in particular polyamides 6-6, and polyesters, in particular polyethylene terephthalate. The polymeric materials can be of the non-thermoplastic type, such as aromatic polyamides, in particular aramid, and cellulose, both natural and artificial, in particular rayon.

Preferably, each corded carcass reinforcement element extends axially from one bead of the tire to the other bead of the tire.

In an advantageous embodiment, the crown reinforcement consists of the working reinforcement and the hooping reinforcement.

By ply, we mean the assembly, on the one hand, of one or more wired reinforcing elements and, on the other hand, of an elastomeric matrix, the wired reinforcing element(s) being embedded in the elastomeric matrix. .

Advantageously, the reinforcing wire elements of each ply are embedded in an elastomeric matrix. The different layers can comprise the same elastomeric matrix or else distinct elastomeric matrices.

In a first embodiment of the tire according to the invention, the working reinforcement comprises two working plies and preferably the working reinforcement consists of two working plies.

In this first embodiment, the work reinforcement wire elements and the carcass reinforcement wire elements are arranged so as to define, in projection on an equatorial circumferential plane in the radial direction of the tire, a triangular mesh. In this first embodiment, the hooping reinforcing wire elements are not necessary to define the triangular mesh.

Advantageously, in this first embodiment, each wired working reinforcement element of each working ply forms an angle ranging from 10° to 40°, preferably ranging from 20° to 30° with the circumferential direction of the tire.

Advantageously, the orientation of the angle made by the wired work reinforcement elements with the circumferential direction of the tire in a work ply is opposite to the orientation of the angle made by the wired work reinforcement elements with the circumferential direction of the tire in the other working ply. In other words, the working reinforcement wire elements of one working ply are crossed with the working reinforcing wire elements of the other working ply.

Advantageously, each corded carcass reinforcement element makes an angle greater than or equal to 80°, preferably ranging from 80° to 90° with the circumferential direction of the tire in the median plane of the tire, in other words in the top of the tire.

Advantageously, each corded carcass reinforcement element makes an angle greater than or equal to 80°, preferably ranging from 80° to 90° with the circumferential direction of the tire in the equatorial circumferential plane of the tire, in other words in each sidewall.

In a second embodiment of the invention, the working reinforcement comprises a single working ply. Thus, the working reinforcement is, with the exception of the working ply, devoid of any ply reinforced by wire reinforcing elements. The wire-like reinforcing elements of such reinforced plies excluded from the working reinforcement of the tire comprise metal wire-like reinforcing elements and textile wire-like reinforcing elements. Very preferably, the working reinforcement consists of a working ply. This embodiment is particularly advantageous when the or each hooping reinforcing wire element consists of a cable as defined above. The mechanical strength and endurance properties of the hooping reinforcement described above then make it possible to remove a working ply from the working reinforcement. A significantly lightened tire is obtained.

In this second embodiment, the hooping reinforcement wire element(s), the working reinforcement wire elements and the carcass reinforcement wire elements are arranged so as to define, in projection on an equatorial circumferential plane in the radial direction of the tire, a triangular mesh. In this second embodiment, unlike the first embodiment, the hooping reinforcing wire elements are necessary to define the triangular mesh.

Advantageously, each carcass reinforcement wire element forms an angle A _C1 greater than or equal to 55°, preferably ranging from 55° to 80° and more preferably ranging from 60° to 70°, with the circumferential direction of the tire in the plane median of the tire, in other words in the crown of the tire. Thus, the carcass reinforcing wire elements, by virtue of the angle formed with the circumferential direction, participate in the formation of the triangular mesh in the crown of the tire.

In one embodiment, each carcass reinforcing wire element forms an angle A _C2 greater than or equal to 85° with the circumferential direction of the tire in the equatorial circumferential plane of the tire, in other words in each sidewall of the tire. The corded carcass reinforcement elements are substantially radial in each sidewall, that is to say substantially perpendicular to the circumferential direction, which makes it possible to retain all the advantages of a tire with radial carcass.

In one embodiment, each wired work reinforcement element makes an angle A _T greater than or equal to 10°, preferably ranging from 30° to 50° and more preferably from 35° to 45° with the circumferential direction of the tire in the median plane of the tire. Thus, the work reinforcement wire elements, by the angle formed with the circumferential direction, participate in the formation of the triangular mesh in the crown of the tire.

In order to form the most effective triangular mesh possible, the orientation of the angle A _T and the orientation of the angle A _C1 are preferably opposite with respect to the circumferential direction of the tire.

• radialement vers l'extérieur, par une surface destinée à être au contact d'un sol et
• radialement vers l'intérieur, par l'armature de sommet.

Whether in the first or the second embodiment of the tire, the crown comprises the tread and the crown reinforcement. By tread is meant a band of polymeric material, preferably elastomeric, delimited:

• radially outwards, by a surface intended to be in contact with the ground and
• radially inwards, by the crown reinforcement.

The strip of polymeric material consists of a ply of a polymeric material, preferably an elastomeric material, or else consists of a stack of several layers, each ply being composed of a polymeric material, preferably an elastomeric material.

Whether in the first or the second embodiment of the tire, the crown reinforcement advantageously comprises a single hooping reinforcement and a single working reinforcement. Thus, the crown reinforcement is, with the exception of the hooping reinforcement and the working reinforcement, devoid of any reinforcement reinforced by reinforcing elements. The reinforcement elements of such reinforcements excluded from the crown reinforcement of the tire include wire reinforcement elements, knits or even fabrics. Very preferably, the crown reinforcement consists of the hooping reinforcement and the working reinforcement.

Whether in the first or the second embodiment of the tire, in a very preferred embodiment, the crown is, with the exception of the crown reinforcement, devoid of any reinforcement reinforced by reinforcing elements. The reinforcing elements of such reinforcements excluded from the crown of the tire include wire reinforcing elements, knits or even fabrics. Very preferably, the crown is made up of the tread and the reinforcement of Mountain peak.

Whether in the first or the second embodiment of the tire, in a very preferred embodiment, the carcass reinforcement is arranged directly radially in contact with the crown reinforcement and the crown reinforcement is arranged directly radially in contact with the tread. In this very preferred embodiment, the single hooping ply and the single working ply are advantageously arranged directly radially in contact with one another.

By directly radially in contact, it is understood that the objects considered directly radially in contact with one another, here the plies, reinforcements or the tread, are not radially separated by any object, for example by any ply, reinforcement nor strip which would be interposed radially between the objects considered directly radially in contact with one another.

Whether in the first or the second embodiment described above, the hooping ply advantageously has a secant modulus in tension greater than or equal to 300 daN.mm ⁻¹ , preferably greater than or equal to 350 daN. mm ^-1 and more preferably greater than or equal to 400 daN.mm ^-1 for a force equal to 15% of the breaking force of the hooping ply. In one embodiment, the hooping ply advantageously has a secant modulus in tension less than or equal to 500 daN.mm ^-1 , preferably less than or equal to 450 daN.mm ^-1 for a force equal to 15% of the force breakage of the hooping ply.

Whether in the first or the second embodiment described above, the breaking force of the hooping ply is greater than or equal to 55 daN.mm ^-1 , preferably greater than or equal to 60 daN.mm ^-1 and more preferably greater than or equal to 65 daN.mm ^-1 . Advantageously, the breaking force of the hooping ply is less than or equal to 85 daN.mm ^-1 , preferably less than or equal to 80 daN.mm ^-1 and more preferably less than or equal to 75 daN.mm ^-1 .

METHOD FOR MANUFACTURING THE TIRE ACCORDING TO THE INVENTION

The tire according to the invention is manufactured according to the method described below.

First of all, each carcass ply, each working ply and each hooping ply are manufactured. Each ply is manufactured by embedding the wire reinforcing elements of each ply in a non-crosslinked elastomeric composition.

Then, the carcass reinforcement, the working reinforcement, the hooping reinforcement and the tread are arranged so as to form a tire blank.

Next, the tire blank is shaped so as to enlarge the tire blank at least radially. This step has the effect of lengthening circumferentially each ply of the tire blank. This step thus has the effect of lengthening the or each wire-based hooping reinforcement element in the circumferential direction of the tire. Thus, the or each wire-based hooping reinforcement element has, before the shaping step, different characteristics from those after the shaping step.

The characteristics of the cord devoid of filler material described above ensure that, at the end of the tire manufacturing process, taking into account the shaping step, the tire will have the advantages described above.

Finally, the compositions of the shaped tire blank are crosslinked, for example by curing or vulcanization, in order to obtain the tire in which each composition has a crosslinked state and forms an elastomeric matrix based on the composition.

• la figure 1 est une vue en coupe radiale d'un pneumatique selon un premier mode de réalisation de l'invention ;
• la figure 2 est une vue en arraché du pneumatique de la figure 1 illustrant la projection sur le plan circonférentiel équatorial E des éléments filaires de renfort de frettage, des éléments filaires de renfort de travail et des éléments filaires de renfort de carcasse ;
• la figure 3 est une vue des éléments filaires de renfort de carcasse agencés dans le flanc du pneumatique de la figure 1 en projection sur le plan médian M du pneumatique ;
• la figure 4 est une vue en coupe perpendiculaire à son axe d'un câble selon l'invention (supposé rectiligne et au repos) ;
• la figure 5 est une vue en perspective du câble de la figure 4 ;
• la figure 6 est une vue en coupe perpendiculaire à son axe d'un câble rempli selon l'invention (supposé rectiligne et au repos) ;
• la figure 7 est une courbe force-allongement de chaque câble des figures 4 et 6 illustrant la variation de la contrainte subie par chaque câble en fonction de l'allongement ainsi que les tangentes à chaque courbe illustrant les modules M₁ et M_c1;
• la figure 8 est une courbe force-allongement de chaque câble des figures 4 et 6 illustrant la variation de la force subie par chaque câble en fonction de l'allongement ainsi que les tangentes à chaque courbe illustrant les modules M₂ et M_c2;
• la figure 9 est une courbe force-allongement de chaque câble des figures 4 et 6 illustrant la variation de la contrainte subie par chaque câble en fonction de l'allongement ainsi que les tangentes à chaque courbe illustrant les modules M₁, et M_c1';
• la figure 10 est une courbe force-allongement de chaque câble des figures 4 et 6 illustrant la variation de la contrainte subie par chaque câble en fonction de l'allongement ainsi que les tangentes à chaque courbe illustrant les modules M_1" et M_c1";
• la figure 11 est une courbe représentant la variation de la dérivée de chaque courbe de la figure 8 en fonction de l'allongement ;
• la figure 12 est une courbe force-allongement équivalente de la nappe de frettage du pneumatique de la figure 1 illustrant la variation de la force subie par la nappe en fonction de l'allongement ainsi que les tangentes à cette courbe illustrant les modules M_n1 et M_n2 ;
• la figure 13 est une courbe force-allongement équivalente de la nappe de frettage du pneumatique de la figure 1 illustrant la variation de la force subie par la nappe en fonction de l'allongement ainsi que les tangentes à cette courbe illustrant les modules M_n1" et M_n2 ;
• la figure 14 est une courbe force-allongement équivalente de la nappe de frettage du pneumatique de la figure 1 illustrant la variation de la force subie par la nappe en fonction de l'allongement ainsi que les tangentes à cette courbe illustrant les modules M_n1" et M_n2 ;
• la figure 15 est une vue analogue à celle de la figure 1 d'un pneumatique selon un deuxième mode de réalisation de l'invention ;
• les figures 16 et 17 sont des vues analogues à celles des vues des figures 2 et 3 du pneumatique de la figure 15 selon le deuxième mode de réalisation de l'invention ;
• les figures 18 et 19 sont des courbes analogues à celles des figures 7 et 8 du câble de la figure 4, du câble rempli de la figure 6 et d'éléments filaires de renfort de frettage de l'état de la technique ; et
• la figure 20 est une courbe force-allongement équivalente de chaque nappe de frettage des pneumatiques des figures 1 et 15 et de pneumatiques de l'état de la technique illustrant la variation de la force subie par la nappe de frettage en fonction de l'allongement ainsi que les tangentes à chaque courbe illustrant les modules M_n1 et M_n2 de chaque nappe de frettage.

The invention will be better understood on reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which:

• the figure 1 is a view in radial section of a tire according to a first embodiment of the invention;
• the figure 2 is a cut-away view of the tire from the figure 1 illustrating the projection onto the equatorial circumferential plane E of the hooping reinforcement wire elements, the working reinforcement wire elements and the carcass reinforcement wire elements;
• the picture 3 is a view of the carcass reinforcement wire elements arranged in the sidewall of the tire of the figure 1 in projection on the median plane M of the tire;
• the figure 4 is a sectional view perpendicular to its axis of a cable according to the invention (assumed straight and at rest);
• the figure 5 is a perspective view of the cable from the figure 4 ;
• the figure 6 is a sectional view perpendicular to its axis of a filled cable according to the invention (assumed straight and at rest);
• the figure 7 is a force-elongation curve of each cable of the figure 4 and 6 illustrating the variation of the stress undergone by each cable as a function of the elongation as well as the tangents to each curve illustrating the modules M ₁ and M _c1 ;
• the figure 8 is a force-elongation curve of each cable of the figure 4 and 6 illustrating the variation of the force undergone by each cable according to the elongation as well as the tangents to each curve illustrating the modules M ₂ and M _c2 ;
• the figure 9 is a force-elongation curve of each cable of the figure 4 and 6 illustrating the variation of the stress undergone by each cable as a function of the elongation as well as the tangents to each curve illustrating the modules M ₁ , and M _c1' ;
• the figure 10 is a force-elongation curve of each cable of the figure 4 and 6 illustrating the variation of the stress undergone by each cable as a function of the elongation as well as the tangents to each curve illustrating the moduli M _1" and M _c1" ;
• the figure 11 is a curve representing the variation of the derivative of each curve of the figure 8 as a function of elongation;
• the figure 12 is an equivalent force-elongation curve of the hooping ply of the tire of the figure 1 illustrating the variation of the force undergone by the ply as a function of the elongation as well as the tangents to this curve illustrating the modules M _n1 and M _n2 ;
• the figure 13 is an equivalent force-elongation curve of the hooping ply of the tire of the figure 1 illustrating the variation of the force undergone by the ply as a function of the elongation as well as the tangents to this curve illustrating the modules M _n1" and M _n2 ;
• the figure 14 is an equivalent force-elongation curve of the hooping ply of the tire of the figure 1 illustrating the variation of the force undergone by the ply as a function of the elongation as well as the tangents to this curve illustrating the modules M _n1" and M _n2 ;
• the figure 15 is a view analogous to that of figure 1 of a tire according to a second embodiment of the invention;
• the figures 16 and 17 are views analogous to those of the views of the figures 2 and 3 of the tire figure 15 according to the second embodiment of the invention;
• the figures 18 and 19 are curves analogous to those of the figures 7 and 8 of the cable from the figure 4 , of the cable filled with the figure 6 and wire-based hooping reinforcing elements of the state of the art; and
• the figure 20 is an equivalent force-elongation curve of each hooping ply of the tires of the figure 1 and 15 and tires of the state of the art illustrating the variation of the force undergone by the hooping ply in function of the elongation as well as the tangents to each curve illustrating the modules M _n1 and M _n2 of each hooping layer.

TIRE ACCORDING TO A FIRST EMBODIMENT OF THE INVENTION

On the figure 1 , a reference X, Y, Z has been shown corresponding to the usual axial (X), radial (Y) and circumferential (Z) directions respectively of a tire.

Schematically represented on the figure 1 , a view in radial section, of a tire according to the invention and designated by the general reference 10. The tire 10 is substantially of revolution around an axis substantially parallel to the axial direction X. The tire 10 is here intended to a passenger vehicle.

The tire 10 comprises a crown 12 comprising a crown reinforcement 14 comprising a working reinforcement 15 comprising two working plies 16, 18 respectively comprising working reinforcing cord elements 46, 47 and a hooping reinforcement 17 comprising a hooping ply 19 comprising at least one hooping reinforcing wire element 48. The crown reinforcement 14 extends in the crown 12 in the circumferential direction Z of the tire 10. The crown 12 comprises a tread 20 arranged radially outside the crown reinforcement 14. Here, the crown 12 is formed by the tread 20 and the crown reinforcement 14. Here, the hooping reinforcement 17, here the hooping ply 19, is radially interposed between the reinforcement 15 and the tread 20. Here, the working reinforcement 15 comprises only two working plies 16, 18 and the hooping reinforcement 17 comprising a single hooping ply 19. Here, the working reinforcement 15 consists of the two working plies 16, 18 and the hooping reinforcement 17 consists of the hooping ply 19. The crown reinforcement 14 consists of the working reinforcement 15 and the hooping reinforcement 17.

The tire 10 also comprises two sidewalls 22 extending the crown 12 radially inwards. The tire 10 further comprises two beads 24 radially inside the sidewalls 22 and each comprising an annular reinforcing structure 26, in this case a bead wire 28, surmounted by a mass of rubber 30 for bead filler, as well as a reinforcement of radial carcass 32. Each sidewall 22 connects each bead 24 to the crown 12.

The carcass reinforcement 32 comprises a carcass ply 34 comprising several carcass reinforcement wire elements 44, the carcass ply 34 being anchored to each of the beads 24 by turning around the bead wire 28, so as to form in each bead 24 a go strand 38 extending from the beads through the sidewalls towards the top 12, and a return strand 40, the radially outer end 42 of the return strand 40 being radially outside the annular reinforcing structure 26. The carcass reinforcement 32 thus extends from the beads 24 in and through the sidewalls 22 as far as the crown 12 and in the crown 12. The carcass reinforcement 32 is arranged radially to the inside the crown reinforcement 14 and the hooping reinforcement 17. The crown reinforcement 14 is therefore radially interposed between the carcass reinforcement 32 and the tread 20. The carcass reinforcement 32 comprises a single and single carcass ply 34. Here, the carcass reinforcement 32 consists of the carcass ply 34.

The tire 10 also comprises an internal sealing layer 46, preferably made of butyl, located axially inside the sidewalls 22 and radially inside the crown reinforcement 14 and extending between the two beads 24.

Each working 16, 18, hooping 19 and carcass 34 ply comprises an elastomeric matrix in which reinforcement elements of the corresponding ply are embedded. Each elastomeric matrix of the working 16, 18, hooping 19 and carcass 34 plies is based on a conventional elastomeric composition for calendering reinforcing elements conventionally comprising a diene elastomer, for example natural rubber, a filler reinforcing agent, for example carbon black and/or silica, a cross-linking system, for example a vulcanization system, preferably comprising sulphur, stearic acid and zinc oxide, and optionally an accelerator and/or vulcanization retarder and/or various additives.

With reference to figures 2 and 3 , each wired carcass reinforcement element 44 extends axially from one bead 24 of the tire 10 to the other bead 24 of the tire 10. Each wired carcass reinforcement element 44 forms an angle A _C greater than or equal to 80° , preferably ranging from 80° to 90°, with the circumferential direction Z of the tire 10 in the median M and circumferential equatorial planes E of the tire 10, in other words in the crown 12 and in each sidewall 22.

With reference to the figure 2 , the working reinforcing wire elements 46, 47 of each working ply 16, 18 are arranged side by side substantially parallel to each other. Each wired work reinforcement element 46, 47 extends axially from one axial end of the work reinforcement 15 of the tire 10 to the other axial end of the work reinforcement 15 of the tire 10. Each wired working reinforcement 46, 48 makes an angle ranging from 10° and 40°, preferably ranging from 20° to 30° and here equal at 26° with the circumferential direction Z of the tire 10 in the median plane M. The orientation of the angle S made by the wirework reinforcing elements 46 with the circumferential direction Z of the tire 10 in the working ply 16 is opposite the orientation of the angle Q made by the wired work reinforcement elements 47 with the circumferential direction Z of the tire 10 in the other work ply 18. In other words, the wired work reinforcement elements 46 of working ply 16 are crossed with the wired working reinforcing elements 47 of the other working ply 18.

With reference to the figure 2 , the single hooping ply 19 comprises at least the hooping reinforcing wire element 48 consisting of or formed by a filled cable 51 according to the invention embedded in the elastomeric matrix of the hooping ply 19 based on the elastomeric composition of the hooping layer 19. The filled cable 51 is described in more detail below with reference to the figure 6 . The filled cable 51 comes from a method of calendering a cable 50 according to the invention in the elastomeric matrix based on the elastomeric composition of the hooping ply 19. The cable 50 is also described in more detail below. in reference to figures 4 and 5 . Thus, the hooping reinforcing wire element 48 is obtained by embedding the cable 50 in an elastomeric matrix based on the elastomeric composition of the hooping ply 19.

In this case, the hooping ply 19 comprises a single wired hooping reinforcement element 48 wound continuously over an axial width L _F of the crown 12 of the tire 10. Advantageously, the axial width L _F is less than the width L _T of the working ply 18. The hooping reinforcing wire element 48 forms an angle A _F strictly less than 10° with the circumferential direction Z of the tire 10, preferably less than or equal to 7°, and more preferably less than or equal to 5°. In this case, the angle here is equal to 5°. d is the density of the hooping reinforcing wire element 48 in the hooping ply 19, expressed as a number per dm of hooping ply 19. Here d=73 dm ⁻¹ .

The carcass 44 and work 46, 47 carcass reinforcement wire elements are arranged, in the crown 12, so as to define, in projection on the equatorial circumferential plane E in the radial direction of the tire, a triangular mesh.

Each carcass reinforcement cord element 44 is a textile cord element and conventionally comprises two multifilament strands, each multifilament strand consisting of a yarn of polyester monofilaments, here of PET, these two multifilament strands being individually overtwisted at 240 turns.m ^-1 in one direction then twisted together at 240 turns.m ^-1 in the opposite direction. These two multifilament strands are helically wound around each other. Each of these multifilament strands has a titer equal to 220 tex.

Each working reinforcing wire element 46, 47 is a metallic wire element and here is an assembly of two steel monofilaments each having a diameter equal to 0.30 mm, the two steel monofilaments being wound one with the other at a pitch of 14 mm.

CABLES ACCORDING TO THE INVENTION

With reference to figures 4, 5 and 6 , each cable 50 and 51 according to the invention comprises a single layer 52 of metal wire elements 54 wound helically. In this case, each cable 50, 51 consists of a single layer 52, in other words each cable 50, 51 does not include any metal wire element other than those of layer 52. Layer 52 consists of N elements metal wires wound in a helix, N ranging from 3 to 6 and here N=4. Each cable 50 and 51 has a main axis A extending substantially parallel to the direction in which the cable extends along its greatest length. Each metal wire element 54 of the layer describes, when each cable 50, 51 extends in a substantially rectilinear direction, a helix-shaped trajectory around the main axis A substantially parallel to the substantially rectilinear direction, so that , in a section plane substantially perpendicular to the main axis A, the distance between the center of each metal wire element 54 of the layer 52 and the main axis A is substantially constant and equal for all the metal wire elements 54 of the layer 52. This constant distance between the center of each metal wire element 54 of layer 52 and the main axis A is equal to half the helix diameter Dh.

In the illustrated embodiment, each metal wire element 54 comprises a single metal monofilament 56. Each metal wire element 54 also includes a layer (not shown) of a metal coating comprising copper, zinc, tin, cobalt or an alloy of these metals, here brass. Each metal monofilament 56 is made of carbon steel and has a mechanical breaking strength here equal to 3100 MPa.

The diameter Df of each metal wire element 54 is such that 0.10 mm ≤ Df ≤ 0.50 mm, preferably 0.20 mm ≤ Df ≤ 0.35 mm and more preferably 0.25 mm ≤ Df ≤ 0.33 mm and here Df=0.32 mm for all the metal wire elements 54. Each metal wire element 54 is devoid of preformation marks.

Each cable 50 and 51 has a diameter D such that D ≤ 2.00 mm, preferably 0.75 mm ≤ D < 1.40 mm and more preferably 1.00 mm ≤ D ≤ 1.30 mm and here D=1 .27mm.

Advantageously, each metallic wire element 54 of each cable 50 and 51 is wound at a pitch P such that 3 mm≤P≤15 mm, preferably 3 mm≤P≤9 mm and here P=8mm.

The ratio K of the pitch P to the diameter Df of each metallic wire element, P and Df being expressed in millimeters, is such that 19≤K≤44 and here K=25.

The metallic wire elements 54 of each cable 50 and 51 define an internal vault 58 of diameter Dv.

With reference to the figure 6 , the filled cable 51 comprises a filling material 53 of the internal vault 58 based on the elastomeric composition of the hooping ply 19, this filling material 53 being located in the internal vault 58 of the cable 51. The cable 50 is, as seen on the figures 4 and 5 , devoid of filling material, that is to say that the internal vault 58 of the cable 50 is empty.

The cable 50 has a structural elongation As such that As ≥ 1%, preferably such that As ≥ 2.5%, more preferably As ≥ 3% and even more preferably such that 3% ≤ As ≤ 5.5% and here equal at 4.8%. As described previously, the As value is determined by plotting a force-elongation curve of the cable 50 by applying the ASTM D2969-04 standard of 2014. The curve obtained is represented on the figure 8 . Then, from this force-elongation curve, the variation of the derivative of this force-elongation curve is deduced therefrom. We represented on the figure 11 the variation of this derivative as a function of the elongation. The highest derivative point then corresponds to the As value.

The helix angle α of each metallic wire element of the cable 50 is such that 13°≤α≤21°. In this case, as described previously, with the characteristics of the cable 50, we have α(1)=20.05°, α(2)=20.36° and α(3)=α=20.37° .

Each metal wire element 54 of cable 50 has a helix radius of curvature Rf such that 2 mm≤Rf≤7 mm, preferably 2 mm≤Rf≤5 mm and more preferably 3 mm≤Rf≤5 mm. The radius of curvature Rf is calculated according to the relationship Rf=P/(π × Sin(2α)). As here P=8 mm and α=20.37°, Rf=3.90 mm.

The helix diameter Dh of each metallic wire element 54 of the cable 50 is such that 0.40 mm≤Dh≤1.50 mm, preferably 0.50 mm≤Dh≤1.00 mm and more preferably 0.70 mm ≤ Dh ≤ 1.00mm. The helix diameter Dh is calculated according to the relation Dh=P × Tan(α) / π. As here P=8 mm and α=20.37°, Dh=0.95 mm.

The arch diameter Dv is calculated according to the relationship Dv=Dh-Df in which Df is the diameter of each metallic wire element and Dh the helix diameter. Advantageously, Dv is such that Dv≥0.46 mm and preferably 0.46 mm≤Dv≤0.70 mm. Here, as Dh=0.95 mm and Df=0.32 mm, we have Dv=0.63 mm.

We have 9≤Rf/Df≤30, and preferably 11≤Rf/Df≤19. Here Rf/Df=12.2. We also have 1.30 ≤ Dv / Df ≤ 2.1, preferably 1.30 ≤ Dv / Df ≤ 2.05 and more preferably 1.30≤Dv/Df≤2.00 and here Dv/Df=1.97.

With reference to the figure 7 on which a force-elongation curve of cable 50 has been drawn by pulling cable 50 under the conditions of standard ASTM D2969-04 of 2014, cable 50 has a modulus M ₁ defined by M ₁ =10 / A ₁₀₀ with A ₁₀₀ being the elongation, expressed in %, of the cable under a force of 100 MPa.

The modulus M ₁ of the cable 50 is, in accordance with the invention, such that ₅ GPa≤M 1≤16 GPa. Furthermore, there is advantageously 6 GPa ≤ M ₁ , preferably 8 GPa ≤ M ₁ . There is also advantageously M ₁ ≤ 14 GPa, preferably M ₁ ≤ 12 GPa. Here, we have M ₁ =8.2 GPa.

• S étant la section, exprimée en mm², telle que S=MI /Mv avec :
  • ▪ MI étant la masse linéique des éléments filaires métalliques, exprimée en g par m de câble,
  • ▪ Mv étant la masse volumique des éléments filaires métalliques, exprimée en g par cm³,
• F₄₀ étant la force, exprimée en daN, égale à 40 % de la force théorique maximale F_t du câble,
• F₃₀ étant la force, exprimée en daN, égale à 30 % de la force théorique maximale F_t du câble,
• A₄₀ étant l'allongement du câble, exprimé en %, à 40% de la force théorique maximale F_t du câble,
• A₃₀ étant l'allongement du câble, exprimé en %, à 30% de la force théorique maximale F_t du câble,

avec F_t= MI × Rm /Mv, exprimée en daN, avec Rm étant la résistance mécanique à rupture moyenne, exprimée en MPa, des éléments filaires métalliques constituant la couche unique.With reference to the figure 8 on which a force-elongation curve of the cable 50 has been drawn by pulling the cable 50 under the conditions of the ASTM D2969-04 standard of 2014, the cable 50 has a modulus M ₂ defined by M ₂ =[(F ₄₀ -F ₃₀ ) / (A ₄₀ -A ₃₀ )] / S with:

• S being the section, expressed in mm ² , such that S=MI /Mv with:
  • ▪ MI being the linear mass of the metallic wire elements, expressed in g per m of cable,
  • ▪ Mv being the density of the metallic wire elements, expressed in g per cm ³ ,
• F ₄₀ being the force, expressed in daN, equal to 40% of the maximum theoretical force F _t of the cable,
• F ₃₀ being the force, expressed in daN, equal to 30% of the maximum theoretical force F _t of the cable,
• A ₄₀ being the elongation of the cable, expressed in %, at 40% of the maximum theoretical force F _t of the cable,
• A ₃₀ being the elongation of the cable, expressed in %, at 30% of the maximum theoretical force F _t of the cable,

with F _t = MI × Rm /Mv, expressed in daN, with Rm being the average breaking strength, expressed in MPa, of the metallic wire elements constituting the single layer.

The modulus M ₂ of the cable 50 is, in accordance with the invention, such that 40 GPa≤M _2≤160 GPa. Furthermore, there is advantageously 65 GPa ≤ M ₂ , preferably 80 GPa ≤ M ₂ and more preferably 90 GPa ≤ M ₂ . There is also advantageously M ₂ ≤ 150 GPa, preferably M ₂ ≤ 140 GPa and more preferably M ₂ ≤ 130 GPa. Here, we have M ₂ =110 GPa

According to the invention, we have 3≤M ₂ /M ₁ . Furthermore, there is advantageously 6≤M ₂ /M ₁ , preferably 8≤M ₂ /M ₁ and more preferably 10≤M ₂ /M ₁ . There is also advantageously M ₂ /M ₁ ≤ 19, preferably M ₂ /M ₁ ≤ 17 and more preferably M ₂ /M ₁ ≤ 15. Here, we have M ₂ /M ₁ =13.4.

With reference to the figure 9 on which a force-elongation curve of the cable 50 has been drawn by pulling the cable 50 under the conditions of the ASTM D2969-04 standard of 2014, the cable 50 has a modulus M ₁ defined by M ₁ =20/A ₂₀₀ with A ₂₀₀ being the elongation, expressed in %, of the cable under a force of 200 MPa. The modulus M ₁ of the cable 50 is such that ₅ GPa≤M 1≤16 GPa. Advantageously, 6 GPa≤M ₁ , preferably 8 GPa≤M _{1 ′} , is also advantageously M 1′≤14 GPa, preferably M _1′≤12 GPa. Here, M _1' =9.1 GPa.

With reference to the figure 10 on which a force-elongation curve of cable 50 has been drawn by pulling cable 50 under the conditions of standard ASTM D2969-04 of 2014, cable 50 has a modulus M _1" defined by M _1" = 30/A ₃₀₀ with A ₃₀₀ being the elongation, expressed in %, of the cable under a force of 300 MPa. The M _1" modulus of the 50 cable is such that 4 GPa ≤ M _1" ≤ 16 GPa. Advantageously there is 6 GPa ≤ M _1" , preferably 8 GPa ≤ M _1" . There is also advantageously M _1" ≤14 GPa, preferably M _1" ≤12 GPa. Here, M _1" = 10.2 GPa.

The cable 51 has a structural elongation Asc such that Asc≥1%, preferably Asc≥1.5%, more preferably Asc≥2% and even more preferably 2%≤Asc≤4% and here equal to 3.3%. As before, the Asc value is determined by plotting a force-elongation curve of the filled cable 51 by applying the ASTM D2969-04 standard of 2014. The curve obtained is represented on the figure 8 . Then, from this force-elongation curve, the variation of the derivative of this force-elongation curve is deduced therefrom. We represented on the figure 11 the variation of this derivative as a function of the elongation. The highest derivative point then corresponds to the Asc value.

With reference to the figure 7 on which a force-elongation curve of the filled cable 51 has been drawn by pulling the filled cable 51 under the conditions of standard ASTM D2969-04 of 2014, the filled cable 51 has a modulus M _c1 defined by M _c1 =10 / A _c100 with A _c100 being the elongation, expressed in %, of the cable filled under a force of 100 MPa,

The modulus M _c1 of the filled cable 51 is, in accordance with the invention, such that 5 GPa≤M _c1≤30 GPa. Furthermore, there is advantageously 7 GPa ≤ M _c1 , preferably 10 GPa ≤ M _c1 . There is also advantageously M _c1 ≤ 25 GPa, preferably M _c1 ≤ 20 GPa. Here, we have M _c1 =11.4 GPa.

• S étant la section, exprimée en mm², telle que S=MI /Mv avec :
  • ▪ MI étant la masse linéique des éléments filaires métalliques, exprimée en g par m de câble dépourvu du matériau de remplissage,
  • ▪ Mv étant la masse volumique des éléments filaires métalliques, exprimée en g par cm³,
• F_c40 étant la force, exprimée en daN, égale à 40 % de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,
• F_c30 étant la force, exprimée en daN, égale à 30 % de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,
• A_c40 étant l'allongement du câble rempli, exprimé en %, à 40% de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,
• A_c30 étant l'allongement du câble rempli, exprimé en %, à 30% de la force théorique maximale F_ct du câble dépourvu du matériau de remplissage,

avec F_ct=MI × Rm / Mv, exprimée en daN, avec Rm étant la résistance mécanique à rupture moyenne, exprimée en MPa, des éléments filaires métalliques constituant la couche unique.With reference to the figure 8 on which a force-elongation curve of the filled cable 51 has been drawn by pulling the filled cable 51 under the conditions of the ASTM D2969-04 standard of 2014, the filled cable 51 has a modulus M _c2 defined by M _c2 =[(F _c40 -F _c30 ) / (A _c40 -A _c30 )] / S with:

• S being the section, expressed in mm ² , such that S=MI /Mv with:
  • ▪ MI being the linear mass of the metallic wire elements, expressed in g per m of cable without filler material,
  • ▪ Mv being the density of the metallic wire elements, expressed in g per cm ³ ,
• F _c40 being the force, expressed in daN, equal to 40% of the maximum theoretical force F _ct of the cable without filling material,
• F _c30 being the force, expressed in daN, equal to 30% of the maximum theoretical force F _ct of the cable without filling material,
• A _c40 being the elongation of the filled cable, expressed in %, at 40% of the maximum theoretical force F _ct of the cable without the filling material,
• A _c30 being the elongation of the filled cable, expressed in %, at 30% of the maximum theoretical force F _ct of the cable without filling material,

with F _ct =MI × Rm / Mv, expressed in daN, with Rm being the average breaking strength, expressed in MPa, of the metal wire elements constituting the single layer.

The modulus M _c2 of the filled cable 51 is, in accordance with the invention, such that 40 GPa≤M _c2≤150 GPa. Furthermore, there is advantageously 60 GPa ≤ M _c2 , preferably 70 GPa ≤ M _c2 and more preferably 80 GPa ≤ M _c2 . There is also advantageously M _c2 ≤ 140 GPa, preferably M _c2 ≤ 130 GPa and more preferably M _c2 ≤ 120 GPa. Here, we have M _c2 =97.5 GPa.

In accordance with the invention, we have 3≤M _c2 /M _c1 . Furthermore, there is advantageously 4≤M _c2 /M _c1 , preferably 5≤M _c2 /M _c1 and more preferably 6≤M _c2 /M _c1 . There is also advantageously M _c2 /M _c1 ≤12, preferably M _c2 /M _c1 ≤11 and more preferably M _c2 /M _c1 ≤10. Here, we have M _c2 /M _c1 =8.5.

With reference to the figure 9 on which a force-elongation curve of the filled cable 51 has been drawn by pulling the filled cable 51 under the conditions of standard ASTM D2969-04 of 2014, the filled cable 51 has a modulus M _c1' defined by M _c1' =20 /A _c200 with A _c200 being the elongation, expressed in %, of the cable filled under a force of 200 MPa. The modulus M _c1' of the filled cable 51 is such that 5 GPa≤M _c1'≤30 GPa. Advantageously, 7 GPa≤M _c1′ , preferably 10 GPa≤M _c1′ , is also advantageously M _c1′≤25 GPa, preferably M _c1′≤20 GPa. Here, M _c1' =13.3 GPa.

With reference to the figure 10 on which a force-elongation curve of the filled cable 51 has been drawn by pulling the filled cable 51 under the conditions of standard ASTM D2969-04 of 2014, the filled cable 51 has a modulus M _c1" defined by M _c1" =30/A _c300 with A _c300 being the elongation, expressed in %, of the filled cable under a force of 300 MPa. The modulus M _c1" of the filled cable 51 is such that 5 GPa ≤ M _c1" ≤ 30 GPa. We advantageously have 7 GPa ≤ M _c1" , preferably 10 GPa ≤ M _c1" . We also advantageously have M _c1" ≤ 25 GPa, preferably M _c1" ≤ 20 GPa. Here, M _c1" =15.6 GPa.

Returning to the tire 10 according to the invention and with reference to the figure 12 on which an equivalent force-elongation curve of the hooping ply 19 has been drawn by pulling a filled cable 51 under the conditions of standard ASTM D2969-04 of 2014 and by multiplying the result by the density d, the hooping ply 19 has a modulus M _n1 defined by M _n1 =250/A _n250 with A _n250 being the equivalent elongation, expressed in %, of the hooping ply 19 under a force of 250 daN.dm ^-1 .

The modulus M _n1 is, in accordance with the invention, such that 100 daN.mm ^-1 ≤ M _n1 ≤ 600 daN.mm ^-1 . Furthermore, there are advantageously 125 daN.mm ^-1 ≤ M _n1 , preferably 150 daN.mm ^-1 ≤ M _n1 . There is also advantageously M _n1 ≤ 500 daN.mm ^-1 , preferably M _n1 ≤ 400 daN.mm ^-1 . In this case, we have M _n1 =283 daN.mm ^-1 .

• F_n40 étant la force, exprimée en daN.dm^-1, égale à 40 % de la force théorique maximale F_nt de la nappe de frettage 19,
• F_n30 étant la force, exprimée en daN.dm^-1, égale à 30 % de la force théorique maximale F_nt de la nappe de frettage 19,
• A_n40 étant l'allongement équivalent de la nappe de frettage, exprimé en %, à 40% de la force théorique maximale F_nt de la nappe de frettage 19,
• A_n30 étant l'allongement équivalent de la nappe de frettage, exprimé en %, à 30% de la force théorique maximale F_nt de la nappe de frettage 19,
  avec F_nt= MI × Rm × d / Mv, exprimée en daN.dm^-1, avec :
  • ▪ MI étant la masse linéique des éléments filaires métalliques 54, exprimée en g par m de câble,
  • ▪ Mv étant la masse volumique des éléments filaires métalliques 54, exprimée en g par cm³,
  • ▪ Rm étant la résistance mécanique à rupture moyenne, exprimée en MPa, des éléments filaires métalliques 54 constituant la couche unique 52, et
  • ▪ d étant la densité du ou des éléments filaires de renfort de frettage 48 dans la nappe de frettage 19, exprimée en nombre par dm de nappe de frettage 19.

Furthermore, the hooping layer 19 has a modulus M _n2 defined by M _n2 =[(F _n40 -F _n30 ) / (A _n40 -A _n30 )] with:

• F _n40 being the force, expressed in daN.dm ^-1 , equal to 40% of the maximum theoretical force F _nt of the hooping layer 19,
• F _n30 being the force, expressed in daN.dm ^-1 , equal to 30% of the maximum theoretical force F _nt of the hooping layer 19,
• A _n40 being the equivalent elongation of the hooping ply, expressed in %, at 40% of the maximum theoretical force F _nt of the hooping ply 19,
• A _n30 being the equivalent elongation of the hooping ply, expressed in %, at 30% of the maximum theoretical force F _nt of the hooping ply 19,
  with F _nt = MI × Rm × d / Mv, expressed in daN.dm ^-1 , with:
  • ▪ MI being the linear mass of the metallic wire elements 54, expressed in g per m of cable,
  • ▪ Mv being the density of the metallic wire elements 54, expressed in g per cm ³ ,
  • ▪ Rm being the average breaking strength, expressed in MPa, of the metallic wire elements 54 constituting the single layer 52, and
  • ▪ d being the density of the hooping reinforcing wire element(s) 48 in the hooping ply 19, expressed as a number per dm of hooping ply 19.

The modulus M _n2 is, in accordance with the invention, such that 1000 daN.mm ^-1 ≤ M _n2 ≤ 4500 daN.mm ^-1 . Furthermore, there are advantageously 1500 daN.mm ^-1 ≤ M _n2 , preferably 1750 daN.mm ^-1 ≤ M _n2 and more preferably 2000 daN.mm ^-1 ≤ M _n2 . There is also advantageously M _n2 ≤ 4000 daN.mm ^-1 , preferably M _n2 ≤ 3800 daN.mm ^-1 and more preferably M _n2 ≤ 3200 daN.mm ^-1 . In this case, we have M _n2 =2418 daN.mm ^-1 .

In accordance with the invention, we have 3≤M _n2 /M _n1 . Furthermore, there is advantageously 4≤M _n2 /M _n1 , preferably 5≤M _n2 /M _n1 and more preferably 6≤M _n2 /M _n1 . There is also advantageously M _n2 /M _n1 ≤12, preferably M _n2 /M _n1 ≤11 and more preferably M _n2 /M _n1 ≤10. In this case, M _n2 /M _n1 =8.5.

With reference to the figure 13 on which an equivalent force-elongation curve of the hooping ply 19 has been drawn by pulling a filled cable 51 under the conditions of standard ASTM D2969-04 of 2014 and by multiplying the result by the density d, the hooping ply 19 has a modulus M _n1' defined by M _n1' =500/A _n500 with A _n500 being the equivalent elongation, expressed in %, of the hooping ply 19 under a force of 500 daN.dm ^-1 . M _n1' is such that 100 daN.mm ^-1 ≤ M _n1' ≤ 600 daN.mm ^-1 . Furthermore, there is advantageously 125 daN.mm ^-1 ≤ M _n1' , preferably 150 daN.mm ^-1 ≤ M _n1' , There is also advantageously M _n1' ≤ 500 daN.mm ^-1 , preferably M _n1' ≤ 400 daN.mm ^-1 . Here, M _n1' =331 daN.mm ^-1 .

With reference to the figure 14 on which an equivalent force-elongation curve of the hooping ply 19 has been drawn by pulling a filled cable 51 under the conditions of standard ASTM D2969-04 of 2014 and by multiplying the result by the density d, the hooping ply 19 has a modulus M _n1" defined by M _n1" =750/A _n750 with A _n750 being the equivalent elongation, expressed in %, of the hooping ply 19 under a force of 750 daN.dm ^-1 . M _n1" is such that 100 daN.mm ^-1 ≤ Mn1" ≤ 600 daN.mm ^-1 . Furthermore, there are advantageously 125 daN.mm ^-1 ≤ M _n1" , preferably 150 daN.mm ^-1 ≤ M _n1" . There is also advantageously M _n1" ≤500 daN.mm ^-1 , preferably M _n1" ≤400 daN.mm ^-1 . Here, M _n1" =388 daN.mm ^-1 .

METHOD FOR MANUFACTURING THE TIRE ACCORDING TO THE FIRST EMBODIMENT

The tire 10 is manufactured according to the method described below.

First of all, the working plies 16, 18 and the carcass ply 34 are manufactured by arranging the wire reinforcing elements of each ply parallel to each other and by embedding them, for example by calendering, in a non-crosslinked composition comprising at least one elastomer, the composition being intended to form an elastomeric matrix once crosslinked. A so-called straight ply is obtained, in which the wire reinforcement elements of the ply are parallel to each other and are parallel to the main direction of the water table. Then, if necessary, portions of each straight ply are cut at a cutting angle and these portions are butted together so as to obtain a so-called angled ply, in which the wire reinforcement elements of the ply are parallel to each other. to each other and form an angle with the main direction of the sheet equal to the angle of cut.

Then, an assembly process is implemented, during which the hooping reinforcement 17, here the hooping sheet 19, is arranged radially outside the working reinforcement 15. In this case, in a first variant, a strip of width B significantly less than L _F is manufactured, in which the hooping reinforcing wire element 48 is formed by a cable 51 embedded in the elastomeric matrix based on the non-crosslinked elastomeric composition of the strip and the strip is wound helically over several turns so as to obtain the axial width L _F . In a second variant, the hooping ply 19 having a width L _F is manufactured in a manner analogous to the carcass and working plies and the hooping ply 19 is wound on one turn on the working reinforcement 15. In a third variant, the hooping reinforcing wire element 48 formed by the cable 50 is wound radially outside the working ply 18, then a layer based on the non-crosslinked elastomeric composition of the hooping ply is deposited thereon 19 and in which will be embedded the hooping reinforcement wire element 48 formed by the cable 50 during the curing of the tire. In the three variants, the bonded reinforcing wire element 48 formed by the cord 50 is embedded in the matrix based on the non-crosslinked elastomeric composition to form, at the end of the tire manufacturing process, the hooping ply 19 comprising the hooping reinforcing wire element 48 obtained by embedding the cable 50 in an elastomeric matrix based on the elastomeric composition of the hooping ply 19. The hooping reinforcing wire element is then formed by the filled cable 51.

Then, the carcass reinforcement, the working reinforcement, the hooping reinforcement and the tread are arranged so as to form a tire blank in which the compositions of the elastomeric matrices are not yet crosslinked and are in a raw state.

Next, the tire blank is shaped so as to enlarge the tire blank at least radially. Finally, the compositions of the shaped tire blank are crosslinked, for example by curing or vulcanization, in order to obtain the tire in which each composition has a crosslinked state and forms an elastomeric matrix based on the composition.

TIRE ACCORDING TO A SECOND EMBODIMENT OF THE INVENTION

We represented on the figures 15 to 17 a tire 10' according to a second embodiment of the invention. In these figures, elements similar to those of the tire 10 according to the first embodiment are designated by identical references.

The tire 10' is substantially of revolution around an axis substantially parallel to the axial direction X. The tire 10' is here intended for a passenger vehicle.

The tire 10' has a crown 12 comprising a tread 20 and a crown reinforcement 14 extending in the crown 12 in the circumferential direction Z.

The crown reinforcement 14 comprises a working reinforcement 15 comprising a single working ply 18 and a hooping reinforcement 17 comprising a single hooping ply 19. Here, the working reinforcement 15 consists of the working ply 18 and the hooping reinforcement 17 consists of the hooping layer 19. The crown reinforcement 14 consists of the working reinforcement 15 and the hooping reinforcement 17.

The crown reinforcement 14 is surmounted by the tread 20. Here, the hooping reinforcement 17, here the hooping ply 19, is radially inserted between the working reinforcement 15 and the tread 20.

The tire 10' comprises two sidewalls 22 extending the crown 12 radially inwards. The tire 10' further comprises two beads 24 radially inside the sidewalls 22 and each comprising an annular reinforcing structure 26, in this case a bead wire 28, surmounted by a mass of rubber 30 for stuffing, as well as a reinforcement of radial carcass 32. The crown reinforcement 14 is located radially between the carcass reinforcement 32 and the tread 20. Each sidewall 22 connects each bead 24 to the crown 12.

The carcass reinforcement 32 comprises a single carcass ply 34. Here, the carcass reinforcement 32 consists of the carcass ply 34. The carcass reinforcement 32 is anchored in each of the beads 24 by a reversal around the rod 28 so as to form in each bead 24 a go strand 38 extending from the beads 24 in the sidewalls 22 and in the crown 12, and a return strand 40, the radially outer end 42 of the return strand 40 being radially the outside of the annular reinforcing structure 26. The carcass reinforcement 32 thus extends from the beads 24 through the sidewalls 22 into the crown 12. In this embodiment, the carcass reinforcement 32 extends also extends axially across the crown 12. The crown reinforcement 14 is radially interposed between the carcass reinforcement 32 and the tread 20.

Each working 18, hooping 19 and carcass 34 ply comprises an elastomeric matrix in which one or more reinforcing elements of the corresponding ply are embedded.

With reference to the figure 16 , the single carcass ply 34 comprises carcass reinforcement wire elements 44. Each carcass reinforcement wire element 44 extends axially from one bead 24 of the tire 10 to the other bead 24 of the tire 10. Each element cord of carcass reinforcement 44 makes an angle A _C1 greater than or equal to 55°, preferably ranging from 55° to 80° and more preferably from 60° to 70°, with the circumferential direction Z of the tire 10 in the median plane M of the tire 10', in other words in the crown 12. With reference to the figure 17 which is a simplified view where, given the scale, all the carcass reinforcement wire elements 44 are shown parallel to each other, each carcass reinforcement wire element 44 forms an angle A _C2 greater than or equal to 85° with the circumferential direction Z of the tire 10' in the equatorial circumferential plane E of the tire 10', in other words in each sidewall 22.

In this example, it is taken as a convention that an angle oriented anti-clockwise from the reference line, here the circumferential direction Z, has a positive sign and that an angle oriented clockwise from the reference line, here the circumferential direction Z, has a negative sign. In this case, A _C1 =+67° and A _C2 =+90°.

With reference to the figure 16 , the single working ply 18 comprises several working reinforcing wire elements 46. The working reinforcing wire elements 46 are arranged side by side substantially parallel to each other. Each wired work reinforcement element 46 extends axially from one axial end of the work reinforcement 15 of the tire 10 to the other axial end of the work reinforcement 15 of the tire 10. Each wired work reinforcement element work 46 forms an angle A _T greater than or equal to 10°, preferably ranging from 30° to 50° and more preferably from 35° to 45° with the circumferential direction Z of the tire 10' in the median plane M. Given the orientation defined previously, A _T =-40

The single hooping ply 19 comprises at least one wired hooping reinforcement element 48. In this case, the hooping ply 19 comprises a single wired hooping reinforcement element 48 wound continuously over an axial width L _F of the crown 12 of the tire 10' so that the axial distance between two adjacent windings is equal to 1.3 mm. Advantageously, the axial width L _F is less than the width L _T of the working ply 18. The hooping reinforcing wire element 48 makes an angle A _F strictly less than 10° with the circumferential direction Z of the tire 10', preferably less than or equal to 7°, and more preferably less than or equal to 5°. In this case, A _F =+5°.

The hooping ply 19 has a secant modulus in tension equal to 430 daN.mm ^-1 for a force equal to 15% of the breaking force of the hooping ply. The breaking strength of the hooping ply is equal to 69 daN.mm ^-1 .

It will be noted that the carcass 44, work 46 and hooping 48 wire elements are arranged, in the crown 12, so as to define, in projection on the equatorial circumferential plane E in the radial direction of the tire, a triangular mesh . Here, the angle A _F and the fact that the orientation of the angle A _T and the orientation of the angle A _C1 are opposite with respect to the circumferential direction Z of the tire 10 ', make it possible to obtain this mesh triangular.

Each carcass reinforcement cord element 44 is a textile cord element and conventionally comprises two multifilament strands, each multifilament strand consisting of a yarn of polyester monofilaments, here of PET, these two multifilament strands being individually overtwisted at 240 turns.m ^-1 in one direction then twisted together at 240 turns.m ^-1 in the opposite direction. These two multifilament strands are helically wound around each other. Each of these multifilament strands has a titer equal to 220 tex.

Each work reinforcement wire element 46 is a metal wire element and is here an assembly of two steel monofilaments each having a diameter equal to 0.30 mm, the two steel monofilaments being wound with each other at a pitch 14mm.

The hooping reinforcing wire element 48 consists of a filled cord 51 as described above. The hooping reinforcing wire element 48 is thus obtained by embedding the cable 50 in an elastomeric matrix based on the elastomeric composition of the hooping ply 19. The hooping ply 19 of the tire 10' has the same properties, in particular the characteristics relating to M _n1 , M _n2 , M _n2 / M _n1 , M _n1' and M _n1" , F _nt , d, MI, Mv, Rm than the hooping ply 19 of the tire 10.

The tire 10' is manufactured by implementing a process similar to the process for manufacturing the tire 10. In order to form the triangular mesh of the tire 10', a specific assembly process is implemented as described in EP1623819 or in FR1413102 .

COMPARATIVE TESTS

• un câble C1 formé par le câble 3.26 décrit dans WO2016/16605 , ce câble C1 étant non conforme à l'invention et obtenu en mettant en oeuvre un procédé classique d'assemblage par retordage de l'état de la technique ;
• un élément filaire de renfort de frettage textile C2 de l'état de la technique formé par un assemblage équilibré en torsions de deux brins de nylon de 140 tex chacun, enroulés en hélice l'un autour de l'autre à 250 tours par mètre ; et
• un élément filaire de renfort de frettage textile C3 de l'état de la technique formé par un assemblage équilibré en torsions d'un premier brin d'aramide de 330 tex, d'un deuxième brin d'aramide de 330 tex et d'un troisième brin de nylon de 188 tex, enroulés à 270 tours par mètre.

The data relating to the cable 50 and to the cable completed 51. We have also gathered in table 1 the data relating to:

• a cable C1 formed by the cable 3.26 described in WO2016/16605 , this cable C1 not being in accordance with the invention and obtained by implementing a conventional method of assembly by twisting of the state of the art;
• a prior art C2 textile hooping reinforcement wire element formed by a torsion-balanced assembly of two nylon strands of 140 tex each, wound helically one around the other at 250 turns per meter; and
• a state-of-the-art C3 textile hooping reinforcement wire element formed by a torsion-balanced assembly of a first strand of 330 tex aramid, a second strand of 330 tex aramid and a third strand of 188 tex nylon, wound at 270 turns per meter.

In table 1, the mention “NS” signifies that the size has no physical meaning for the wired element of textile hooping reinforcement considered.

For C2 and C3 textile hooping reinforcement wire elements, the linear density is defined as the sum of the counts (or linear density) of each strand, each count being determined according to the ASTM D885/D 885M - 10a standard of 2014. density is determined by the density of the strands, weighted on average by the titles of each strand in the case of the C3 element, with approximately 1.44 g.cm ^-3 for aramid and 1.14 g.cm ^-3 for nylon. The maximum theoretical force F _t is defined as the breaking force of each wired textile hooping reinforcement element determined according to the ASTM D885/D 885M - 10a standard of 2014. The other characteristics are determined in the same or analogous way.

The force-elongation curves of these cords and wired textile hooping reinforcement elements are gathered on the figures 18 and 19 .

• un pneumatique P1 identique au pneumatique 10' à l'exception de la nappe de frettage qui comprend l'élément de renfort de frettage C1 ;
• un pneumatique P2 identique au pneumatique 10' à l'exception de la nappe de frettage qui comprend l'élément de renfort de frettage C2 ; et
• un pneumatique P3 identique au pneumatique 10' à l'exception de la nappe de frettage qui comprend l'élément de renfort de frettage C3.

The data relating to the tire 10' according to the invention has been collated in table 2. We have also gathered in table 2 the data relating to:

• a tire P1 identical to tire 10' with the exception of the hooping ply which comprises the hooping reinforcing element C1;
• a tire P2 identical to tire 10' with the exception of the hooping ply which comprises the hooping reinforcing element C2; and
• a tire P3 identical to tire 10' with the exception of the hooping ply which comprises the hooping reinforcing element C3.

The force-elongation curves of the hooping plies of these tires are shown on the figure 20 .

Table 3 shows the results of the tests aimed at evaluating the noise emitted by the tire and the shrink fit of each tire.

Noise

Noise is evaluated by simulation for cost and speed reasons. Several tires are actually tested under the conditions of the ISO13325:2003 standard and a relationship is established in the form of a chart between the theoretical radiated sound power of each of these tires and the noise actually measured, a chart taking particular account of the influence of the conformation step. Then, the theoretical radiated acoustic power of each tire P1, P2, P3 and 10' is determined and, using the chart constructed previously, the value of the noise emitted is determined. The results have been presented taking as reference noise the noise emitted by the tire P1 and the noise gain of each tire tested relative to the tire P1 has been indicated.

Shrinking

As already mentioned above, the hooping capacity of a hooping reinforcing wire element or of a hooping ply comprising this hooping reinforcing wire element is given by the value of the modulus M ₂ , M _c2 and M _n2 . The higher the value of this modulus M ₂ , M _c2 and M _n2 , the better the hooping of the tire.

Cost

The cost is the estimate of the cost of manufacturing a hooping ply according to the average cost of the raw materials but also the cost associated with the manufacturing process of the hooping ply and therefore in particular the manufacturing process of each wire element of reinforcement. The cost is given by reference to the hooping ply of the tire P2 which is the least expensive.

The tire P1 has the ply having the highest shrinking capacity. Nevertheless, due to a very high modulus M ₁ , M _c1 and M _n1 , the tire P1 is very noisy.

The tire P2 has a hooping ply with very low hooping properties that does not allow effective hooping of the tire under high stresses. The corded textile reinforcement element C2 is particularly inappropriate for a tire in which the working reinforcement consists of a single working ply and in which the hooping reinforcement absorbs a significant part of the forces. In the case of a tire in which the working reinforcement consists of two working plies, the hooping reinforcement would not have to take up this important part of effort and the wired textile reinforcement element C2 could therefore be more appropriate but without providing sufficient hooping capacity in the case of very high stresses.

The tire P3 has a hooping ply with properties superior to those of the tire P2 and a sound level lower than the tire P1. Even if the shrinking capacity is sufficient, it is still less than that of the P1 and 10' tires. In addition, the tire P3 uses wire elements comprising aramid, which makes it a much more expensive wire element than the metal wire elements of the tires P1 and 10'.

The tire 10' has, in accordance with the invention, a hooping ply that is both effective (only the tire P1 has a higher hooping capacity), low noise and very inexpensive compared to the hooping ply of the tire P3. The wired reinforcing elements 50 and 51 are, due to their excellent hooping capacity, particularly suitable for a tire in which the working reinforcement consists of a single working ply and in which the hooping reinforcement takes up a part of the forces that would be taken up by the two working plies of a tire comprising a working reinforcement made up of two working plies. The wire reinforcement elements 50 and 51 are also particularly suitable in the case of a tire in which the working reinforcement is made up of two working plies and in which it would thus be possible to very significantly reinforce the hoop capacity of the tire while reducing the noise emitted. <b>Table 1</b> At ₁₀₀ (%) At ₂₀₀ (%) At ₃₀₀ (%) F ₄₀ (daN) F ₃₀ (daN) At ₄₀ (%) At ₃₀ (%) MI (gm ^-1 ) Mv (g.cm ^-3 ) Rm (MPa) F _t (daN) M1 ₍ GPa) _M2 (GPa) M1, ₍ GPa) M _1" (GPa) _M2 / _M1 ace C1 0.13 0.21 0.27 20.2 15.1 0.80 0.61 1270 7.8 3100 50 75 162 93.5 110 2.2 <1% C2 3.30 6.50 8.46 9.6 7.2 9.39 7.90 305 1.14 / 24 3.0 6.0 3.1 3.5 2.0 NS C3 1.26 2.15 2.78 44.1 33.1 4.46 3.78 900 1.37 / 110 7.9 24.8 9.3 10.8 3.1 NS 50 1.22 2.21 2.95 42.3 31.7 5.16 4.88 2660 7.8 3100 106 8.2 110 9.1 10.2 13.4 4.8% At ₁₀₀ (%) At ₂₀₀ (%) At ₃₀₀ (%) F ₄₀ (daN) F ₃₀ (daN) At ₄₀ (%) At ₃₀ (%) MI (gm ^-1 ) Mv (g.cm ^-3 ) Rm (MPa) F _t (daN) M _c1 (GPa) M _c2 (GPa) M _c1' (GPa) M _c1" (GPa) M _c2 / M _c1 Asc 51 0.88 1.50 1.92 42.3 31.7 3.29 2.97 2660 7.8 3100 106 11.4 97.5 13.3 15.6 8.5 3.3% At _n250 (%) At _n500 (%) At _n750 (%) F _n40 (daN.dm ^-1 ) F _n30 (daN.dm ^-1 ) At _n40 (%) At _n30 (%) MI (gm ^-1 ) Mv (g.cm ^-3 ) Rm (MPa) _Fnt (daN. dm ^-1 ) Mn1 (daN. mm ^-1 ) M _n2 (daN. mm ^-1 ) M _n1' (daN. mm ^-1 ) M _n1" (daN. mm ^-1 ) Mn2 / _Mn1 d (dm- ¹ ) P1 0.2 0.2 0.3 3107 2330 0.80 0.61 1270 7.8 3100 6142 1630 3516 2339 2764 2.2 133 P2 2.1 5.2 7.1 1179 884 9.39 3.78 305 1.14 / 2946 121 197 95 105 1.6 123 P3 0.7 1.3 1.8 3299 2474 4.46 7.90 900 1.37 / 8248 346 1214 389 421 3.5 75 10' 0.9 1.5 1.9 3075 2307 3.29 2.97 2660 7.8 3100 6500 283 2418 331 388 8.5 73 noise gain Shrinking capacity Cost P1 0dB excellent ++ P2 4.7dB Poor + P3 3.8dB Good +++++ 10' 3.8dB Very good ++

Claims (15)

1. Cord (50) comprising a single layer (52) of helically wound metal filamentary elements (54), each metal filamentary element (54) of the layer (52) describing, when the cord (50) extends in a substantially rectilinear direction, a helical path about a main axis (A) substantially parallel to the substantially rectilinear direction, such that, in a section plane substantially perpendicular to the main axis (A), the distance between the centre of each metal filamentary element (54) of the layer (52) and the main axis (A) is substantially constant and identical for all the metal filamentary elements (54) of the layer (52), characterized in that:

   - 5 GPa ≤ M₁ ≤ 16 GPa, and

   - 40 GPa ≤ M₂ ≤ 160 GPa, and

   - 3 ≤ M₂/M₁,

   M₁ and M₂ being expressed in GPa, where:

   - M₁=10 / A₁₀₀, where:

   - A₁₀₀ is the elongation, expressed in %, of the cord under a load of 100 MPa, and

   - M₂=[(F₄₀-F₃₀) / (A₄₀-A₃₀)] / S, where:

   - S is the cross-sectional area, expressed in mm², such that S=MI /Mv, where:

   ▪ Ml is the linear density of the metal filamentary elements (54), expressed in g per m of cord,

   ▪ Mv is the mass density of the metal filamentary elements (54), expressed in g per cm³,

   - F₄₀ is the force, expressed in daN, equal to 40% of the theoretical maximum force F_t of the cord,

   - F₃₀ is the force, expressed in daN, equal to 30% of the theoretical maximum force F_t of the cord,

   - A₄₀ is the elongation of the cord, expressed in %, at 40% of the theoretical maximum force F_t of the cord,

   - A₃₀ is the elongation of the cord, expressed in %, at 30% of the theoretical maximum force F_t of the cord,

   where F_t= Ml x Rm /Mv, expressed in daN, where Rm is the mean tensile strength, expressed in MPa, of the metal filamentary elements (54) making up the single layer (52).
2. Cord (50) according to the preceding claim, wherein 6 ≤ M₂/M₁, preferably 8 ≤ M₂/M₁ and more preferably 10 ≤ M₂/M₁.
3. Cord (50) according to either one of the preceding claims, wherein M₂/M₁ ≤ 19, preferably M₂/M₁ ≤ 17 and more preferably M₂/M₁ ≤ 15.
4. Cord (50) according to any one of the preceding claims, having a structural elongation As such that As ≥ 1%, preferably As ≥ 2.5%, more preferably As ≥ 3% and even more preferably 3% ≤ As ≤ 5.5%, the structural elongation As being determined by applying the standard ASTM D2969-04 of 2014 to the cord so as to obtain a force-elongation curve, the structural elongation As being equal to the elongation, in %, corresponding to the maximum gradient of the force-elongation curve.
5. Filled cord (51) comprising a single layer (52) of helically wound metal filamentary elements (54), each metal filamentary element (54) of the layer (52) describing, when the cord (50) extends in a substantially rectilinear direction, a helical path about a main axis (A) substantially parallel to the substantially rectilinear direction, such that, in a section plane substantially perpendicular to the main axis (A), the distance between the centre of each metal filamentary element (54) of the layer (52) and the main axis (A) is substantially constant and identical for all the metal filamentary elements (54) of the layer (52), the metal filamentary elements (54) defining an internal enclosure (58) of the cord (51), the filled cord (51) comprising a filling material (53) for the internal enclosure (58) that is based on an elastomeric composition and situated in the internal enclosure (58) of the filled cord (51), characterized in that:

   - 5 GPa ≤ M_c1 ≤ 30 GPa, and

   - 40 GPa ≤ M_c2 ≤ 150 GPa, and

   - 3 ≤ M_c2/M_c1,

   M_c1 and M_c2 being expressed in GPa, where:

   - M_c1=10 / A_c100, where:

   - A_c100 is the elongation, expressed in %, of the filled cord (51) under a load of 100 MPa, and

   - M_c2=[(F_c40-F_c30) / (A_c40-A_c30)] / S, where:

   - S is the cross-sectional area, expressed in mm², such that S=MI /Mv, where:

   ▪ Ml is the linear density of the metal filamentary elements (54), expressed in g per m of cord,

   ▪ Mv is the mass density of the metal filamentary elements (54), expressed in g per cm³,

   - F_c40 is the force, expressed in daN, equal to 40% of the theoretical maximum force F_ct of the cord without filling material,

   - F_c30 is the force, expressed in daN, equal to 30% of the theoretical maximum force F_ct of the cord without filling material,

   - A_c40 is the elongation of the filled cord, expressed in %, at 40% of the theoretical maximum force F_ct of the cord without filling material,

   - A_c30 is the elongation of the filled cord, expressed in %, at 30% of the theoretical maximum force F_ct of the cord without filling material,

   where F_ct= Ml x Rm / Mv, expressed in daN, where Rm is the mean tensile strength, expressed in MPa, of the metal filamentary elements (54) making up the single layer (52).
6. Filled cord (51) according to Claim 5, wherein 4 ≤ M_c2/M_c1, preferably 5 ≤ M_c2/M_c1 and more preferably 6 ≤ M_c2/M_c1.
7. Filled cord (51) according to Claim 5 or 6, wherein M_c2/M_c1 ≤ 12, preferably M_c2/M_c1 ≤ 11 and more preferably M_c2/M_c1 ≤ 10.
8. Filled cord (51) according to any one of Claims 5 to 7, having a structural elongation Asc such that Asc ≥ 1%, preferably Asc ≥ 1.5%, more preferably Asc ≥ 2% and even more preferably 2% ≤ Asc ≤ 4%, the structural elongation Asc being determined by applying the standard ASTM D2969-04 of 2014 to the filled cord so as to obtain a force-elongation curve, the structural elongation Asc being equal to the elongation, in %, corresponding to the maximum gradient of the force-elongation curve.
9. Tyre (10, 10') comprising a crown (12) comprising a tread (20) and a crown reinforcement (14), two sidewalls (22), two beads (24), each sidewall (22) connecting each bead (24) to the crown (12), the crown reinforcement (14) extending in the crown (12) in a circumferential direction (Z) of the tyre (10), the tyre (10) comprising a carcass reinforcement (32) that is anchored in each of the beads (24) and extends in the sidewalls (22) and in the crown (12), the crown reinforcement (14) being radially interposed between the carcass reinforcement (32) and the tread (20),

   the crown reinforcement (14) comprising a hoop reinforcement (17) comprising at least one hooping ply (19) comprising at least one hooping filamentary reinforcing element (48) embedded in an elastomeric matrix based on an elastomeric composition and a working reinforcement (15) comprising at least one working ply (16, 18) comprising working filamentary reinforcing elements (46, 47),

   the carcass reinforcement (32) comprising at least one carcass ply (34) comprising carcass filamentary reinforcing elements (44),

   at least the working filamentary reinforcing elements (46, 47) and the carcass filamentary reinforcing elements (44) being arranged so as to define a triangle mesh in projection onto the equatorial circumferential plane (E) in the radial direction (Y) of the tyre, characterized in that the or each hooping filamentary reinforcing element (48) is formed by a filled cord (51) comprising a single layer of helically wound metal filamentary elements (54), the metal filamentary elements (54) defining an internal enclosure (58) of the filled cord (51), the filled cord (51) comprising a filling material (53) for the internal enclosure (58) that is based on the elastomeric composition and situated in the internal enclosure (58) of the filled cord (51), characterized in that the filled cord (51), once it has been extracted from the tyre (10; 10'), is according to any one of Claims 5 to 8.
10. Tyre (10; 10') comprising a crown (12) comprising a tread (20) and a crown reinforcement (14), two sidewalls (22), two beads (24), each sidewall (22) connecting each bead (24) to the crown (12), the crown reinforcement (14) extending in the crown (12) in a circumferential direction (Z) of the tyre (10), the tyre (10) comprising a carcass reinforcement (32) that is anchored in each of the beads (24) and extends in the sidewalls (22) and in the crown (12), the crown reinforcement (14) being radially interposed between the carcass reinforcement (32) and the tread (20),

    the crown reinforcement (14) comprising a hoop reinforcement (17) comprising at least one hooping ply (19) comprising at least one hooping filamentary reinforcing element (48) embedded in an elastomeric matrix based on an elastomeric composition and a working reinforcement (15) comprising at least one working ply (16, 18) comprising working filamentary reinforcing elements (46, 47),

    the carcass reinforcement (32) comprising at least one carcass ply (34) comprising carcass filamentary reinforcing elements (44),

    at least the working filamentary reinforcing elements (46, 47) and the carcass filamentary reinforcing elements (44) being arranged so as to define a triangle mesh in projection onto the equatorial circumferential plane (E) in the radial direction (Y) of the tyre, the or each hooping filamentary reinforcing element (48) being formed by a filled cord (51) comprising a single layer of helically wound metal filamentary elements (54), each metal filamentary element (54) of the layer (52) describing, when the cord (50) extends in a substantially rectilinear direction, a helical path about a main axis (A) substantially parallel to the substantially rectilinear direction, such that, in a section plane substantially perpendicular to the main axis (A), the distance between the centre of each metal filamentary element (54) of the layer (52) and the main axis (A) is substantially constant and identical for all the metal filamentary elements (54) of the layer (52), the metal filamentary elements (54) defining an internal enclosure (58) of the filled cord (51), the filled cord (51) comprising a filling material (53) for the internal enclosure (58) that is based on the elastomeric composition and situated in the internal enclosure (58) of the filled cord (51), characterized in that the hooping ply (19), once it has been extracted from the tyre (10; 10'), has the following characteristics:

    - 100 daN.mm^-1 ≤ M_n1 ≤ 600 daN.mm^-1, and

    - 1000 daN.mm^-1 ≤ M_n2 ≤ 4500 daN.mm^-1, and

    - 3 ≤ M_n2/M_n1,

    M_n1 et M_n2 being expressed in daN.mm^-1, where

    - M_n1=250 / A_n250, where:

    - A_n250 is the equivalent elongation, expressed in %, of the hooping ply (19) under a load of 250 daN.dm^-1, A_n250 being obtained by dividing the load of 250 daN.dm^-1 by the density of hooping filamentary reinforcing elements (48) per decimetre of hooping ply (19) so as to obtain a unitary load, then by determining, from a force-elongation curve obtained by tensioning the filled cord (51) under the conditions of the standard ASTM D2969-04 of 2014, the elongation of the filled cord (51) under this unitary load, and

    - M_n2=[(F_n40-F_n30) / (A_n40-A_n30)], where:

    - F_n40 is the force, expressed in daN.dm^-1, equal to 40% of the theoretical maximum force F_nt of the hooping ply (19),

    - F_n30 is the force, expressed in daN.dm^-1, equal to 30% of the theoretical maximum force F_nt of the hooping ply (19),

    - A_n40 is the equivalent elongation of the hooping ply, expressed in %, at 40% of the theoretical maximum force F_nt of the hooping ply (19), A_n40 being obtained by dividing 40% of the theoretical maximum force F_nt of the hooping ply (19) by the density d of hooping filamentary reinforcing elements (48) per decimetre of hooping ply (19) so as to obtain a unitary load at 40%, then by determining, from a force-elongation curve obtained by tensioning the filled cord (51) under the conditions of the standard ASTM D2969-04 of 2014, the elongation of the filled cord (51) under this unitary load,

    - A_n30 is the equivalent elongation of the hooping ply, expressed in %, at 30% of the theoretical maximum force F_nt of the hooping ply (19), A_n30 being obtained by dividing 30% of the theoretical maximum force F_nt of the hooping ply (19) by the density d of hooping filamentary reinforcing elements (48) per decimetre of hooping ply (19) so as to obtain a unitary load at 30%, then by determining, from a force-elongation curve obtained by tensioning the filled cord (51) under the conditions of the standard ASTM D2969-04 of 2014, the elongation of the filled cord (51) under this unitary load,

    where F_nt= Ml x Rm x d / Mv, expressed in daN.dm^-1, where:

    ▪ Ml is the linear density of the metal filamentary elements (54), expressed in g per m of cord,

    ▪ Mv is the mass density of the metal filamentary elements (54), expressed in g per cm³,

    ▪ Rm is the mean tensile strength, expressed in MPa, of the metal filamentary elements (54) making up the single layer (52), and

    ▪ d is the density of the one or more hooping filamentary reinforcing elements in the hooping ply (19), expressed in number per dm of hooping ply (19).
11. Tyre (10; 10') according to Claim 10, wherein 4 ≤ M_n2/M_n1, preferably 5 ≤ M_n2/M_n1 and more preferably 6 ≤ M_n2/M_n1.
12. Tyre (10; 10') according to Claim 10 or 11, wherein M_n2/M_n1 ≤ 12, preferably Mn₂/Mn₁ ≤ 11 and more preferably M_n2/M_n1 ≤ 10.
13. Tyre (10; 10') according to any one of Claims 10 to 12, wherein the hoop reinforcement comprises a single hooping ply.
14. Tyre (10') according to any one of Claims 10 to 13, wherein the working reinforcement comprises a single working ply.
15. Tyre (10') according to the preceding claim, wherein the one or more hooping filamentary reinforcing elements (48), the working filamentary reinforcing elements (46) and the carcass filamentary reinforcing elements (44) are arranged so as to define a triangle mesh in projection onto the equatorial circumferential plane (E) in the radial direction (Y) of the tyre.

Images